supplementary materials, part i questionnairedownload.lww.com/wolterskluwer_vitalstream_com/... ·...
TRANSCRIPT
1
The Impact of Laboratory Practices on Inter-laboratory Variability in Therapeutic Drug Monitoring of Immunosuppressive Drugs. Christians U, MD, PhD1, Vinks S, PharmD, PhD2, Langman L, PhD3, Clarke W, PhD4, Wallemacq P, PhD6, Van Gelder T, MD, PhD7, Renjen V, MD8, Marquet P, MD, PhD5, Meyer EJ, BS9 1iC42 Clinical Research and Development, University of Colorado, Aurora, CO, USA; 2Cincinnati Children’s Hospital and Medical Center; 3Mayo Clinic, Rochester MN, USA; 4John Hopkins School of Medicine, Baltimore, Maryland, USA; 5Cliniques Universitaires St. Luc UCL, Brussels, Belgium; 6Erasmus Medical Center, Rotterdam, The Netherlands; 7Navigant Consulting Inc., New York, NY, USA; 8University Hospital of Limoges, Limoges, France; 9Novartis Pharmaceutical Corp., East Hannover, NJ, USA
SUPPLEMENTARY MATERIALS, PART I Questionnaire
2
PROJECT: PRECISION
Assessment of Inter-lab Variability of TDM Analytical Assays for Immunosuppressant Drugs
QUESTION FLOW OF THE SURVEY:
A. SCREENER – RESPONDENT & LAB PROFILE:
B. PROCESS OF CONDUCTING TDM ANALYTICAL ASSAYS:
C. TDM ANALYTICAL ASSAY DEVELOPMENT:
D. TDM ANALYTICAL ASSAY VALIDATION:
E. TDM ANALYTICAL ASSAY IMPLEMENTATION:
F. TDM ANALYTICAL ASSAY QC:
G. PROFICIENCY TEST:
H. HYPOTHESIS FOR INTER-LAB VARIABILITY OF TDM ANALYTICAL ASSAYS:
TABLE COLOR KEY:
Questions relevant to all TDM analytical assay methods
Questions related to immunoassays only
Questions related to mass spectrometry only
Questions related to HPLC-UV only
Respondent Profile Lab Profile
Sam. Acq. & Samp. Prep. & Ext. Conduct of Assays QA / QC
Assay Development
Assay Validation
Assay Implement.
Control / QC
Proficiency Test
Hypotheses
3
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
A. SCREENER – RESPONDENT & LAB PROFILE:
1. Please indicate the name of your laboratory:
(This question is for sample control purpose only. Your answer will not be shared with
an outside party.)
____________________
2. Please provide your current job title:
# Title Select all that apply
1 Lab Director / Medical Director
2 Lab Manager / Supervisor
3 Lab technician
4 Other, please specify: __________
3. Please indicate your educational background:
# Education Select all that apply
1 Ph.D.
2 M.D.
3 Masters
4 Bachelors
5 Other, please specify: __________
4. How many years in total have you been performing or supervising TDM analytical
assays for immunosuppressant drugs?
# Years Select One
1 < 1 year
2 1 – 2 years
3 2 – 5 years
4 > 5 years
Lab Profile
Respondent Profile
Respondent Profile
Respondent Profile
4
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
5. How many years have you been in this lab?
# Years Select One
1 < 1 year
2 1 – 2 years
3 2 – 5 years
4 > 5 years
6. Approximately, how many employees work at your laboratory site / facility?
# Number of Employees Select One
1 < 20
2 20 – 100
3 100 – 500
4 500 – 2,000
5 > 2,000
7. How many people perform TDM analytical assays in your lab?
# # of People Performing TDM
Assays
Select One
1 1 – 3
2 4 – 6
3 7 – 10
4 11 – 20
5 More than 20
8. In your lab, which type of TDM analytical assays is the primary one performed for the
following immunosuppressant drugs?
Select One
# TDM Analytical Assay Method cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Immunoassay
Respondent Profile
Lab Profile
Lab Profile
Lab Profile
5
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
2 Mass spectrometry
3 HPLC-UV
4 Others, please specify:
__________
5 Currently not performing TDM
analytical assays for the
indicated immunosuppressant
9. What are all of the TDM analytical assay methods, instrumentation systems, and/or kits
that are available in your lab ,or are in the process of being implemented, for the testing
of the following immunosuppressant drugs (please select all)?
Select all that apply
# Immunoassay Methods cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 ACMIA
2 ADVIA
3 CEDIA
4 CMIA
5 EMIT
6 FPIA
7 MEIA
8 QMS
9 Manual ELISA
10 Others, please specify:
__________
Select all that apply
# Immunoassay Instrumentation
Systems
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Abbott Architect c Series
2 Abbott Architect i Series
3 Abbott AxSYM
4 Abbott IMx
5 Abbott TDx
6 Beckman Access
7 Beckman UniCel DxC Access
Series
Lab Profile
6
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
8 Beckman UniCel Dxl Access
Series
9 Olympus AU Series
10 Ortho VITROS Series
11 Roche COBAS Series
12 Roche Elecsys
13 Roche Hitachi 917
14 Roche Modular
15 Siemens ADVIA Centaur
16 Siemens ADVIA 1250
17 Siemens ADVIA 1650
18 Siemens ADVIA 1800
19 Siemens Dimension EXL
20 Siemens Dimension RxL
21 Siemens Dimension Vista
22 Siemens Dimension Xpand
23 Siemens IMMULITE
24 Thermo Scientific Indiko
25 Thermo CDx 90
26 Thermo Scientific MGC 240
27 Manual ELISA
28 Other, please specify:
__________
Please select all that apply & specify model numbers
# Mass Spectrometer
Manufacturer
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Agilent
2 AB Sciex
3 Bruker
4 Thermo Scientific
5 Waters
6 Others, please specify:
__________
Select all that apply
# Mass Spectrometer Kit cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Waters MassTrak
2 Chromsystems MassTox
3 Recipe ClinMass
7
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
4 Developed in house
5 Others, please specify:
__________
10. What is the primary TDM assay instrumentation system and/or kit that your lab uses for
the following immunosuppressant drugs?
Select all that apply
# Immunoassay Methods cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 ACMIA
2 ADVIA
3 CEDIA
4 CMIA
5 EMIT
6 FPIA
7 MEIA
8 QMS
9 Manual ELISA
10 Others, please specify:
__________
Select all that apply
# Immunoassay Instrumentation
Systems
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Abbott Architect c Series
2 Abbott Architect i Series
3 Abbott AxSYM
4 Abbott IMx
5 Abbott TDx
6 Beckman Access
7 Beckman UniCel DxC Access
Series
8 Beckman UniCel Dxl Access
Series
9 Olympus AU Series
10 Ortho VITROS Series
11 Roche COBAS Series
Lab Offering
8
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
12 Roche Elecsys
13 Roche Hitachi 917
14 Roche Modular
15 Siemens ADVIA Centaur
16 Siemens ADVIA 1250
17 Siemens ADVIA 1650
18 Siemens ADVIA 1800
19 Siemens Dimension EXL
20 Siemens Dimension RxL
21 Siemens Dimension Vista
22 Siemens Dimension Xpand
23 Siemens IMMULITE
24 Thermo Scientific Indiko
25 Thermo CDx 90
26 Thermo Scientific MGC 240
27 Manual ELISA
28 Other, please specify:
__________
Please select all that apply & specify model numbers
# Mass Spectrometer
Manufacturer
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Agilent
2 AB Sciex
3 Bruker
4 Thermo Scientific
5 Waters
6 Others, please specify:
__________
Select all that apply
# Mass Spectrometer Kit cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Waters MassTrak
2 Chromsystems MassTox
3 Recipe ClinMass
4 Developed in house
5 Others, please specify:
__________
9
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
11. Does your lab test the following immunosuppressant drugs using TDM analytical assays
for clinical or research purpose?
Select One
# Clinical or Research? cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 For clinical purpose
2 For research purpose
3 Both
12. Your laboratory is affiliated with:
# Affiliation Select all that apply
1 A university
2 A research center
3 A hospital
4 A transplant center
5 A commercial lab
13. In which country does your lab reside?
____________________ (SCROLL DOWN / DROP DOWN MENU)
COUNTRY LIST:
U.S.
Germany
France
Belgium
Italy
Spain
UK
Netherlands
Denmark
Norway
Sweden
Brazil
Mexico
Lab Profile
Lab Profile
Lab Profile
10
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
Australia
South Africa
India
Russia
South Korea
Taiwan
Argentina
14. Please provide the zip code or postal code of your laboratory’s location:
____________________
15. From where does your lab typically receive samples for TDM analytical assays of the
following immunosuppressant drugs?
Select the most representative area for each compound
# Geographic Span cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Local (within hospital or
community)
2 Regional
3 National
4 International
5 Not sure
16. Approximately how many patient samples does your laboratory run each month using
the primary TDM analytical method for each of the following immunosuppressant
drugs?
Select One
# Monthly Volume of TDM Assays cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 < 500
2 500 - 1,000
3 1,000 – 2,000
Lab Profile
Lab Profile
Lab Profile
11
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
4 2,000 – 4000
5 > 4,000
17. Does your lab have a formal training procedure for people who perform TDM analytical
assays for immunosuppressant drugs?
# Training Procedure Select One
1 No
2 Yes
3 Not sure
18. What is the minimal experience level of the people performing TDM analytical assays in
your lab?
# Minimal Experience Level Select One
1 0 – 3 months
2 3 – 6 months
3 6 – 12 months
4 More than 1 year
19. What is the maximal experience level of the people performing TDM analytical assays in
your lab?
# Maximal Experience Level Select One
1 < 6 months
2 6 – 12 months
3 1 – 3 years
4 > 3 years
20. Please indicate what percentage of your professional time is spent in the lab or managing
the lab (vs. teaching, conducting research, etc.)
Lab Profile
Lab Profile
Lab Profile
Respondent Profile
12
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
# % Time Spent Select One
1 < 25%
2 25 – 50%
3 50 – 75%
4 75 – 100%
21. On a scale of 1 to 7, how experienced are you with the following activities?
(1 means “no experience” and 7 means “very experienced”)
Experience 1 2 3 4 5 6 7
Knowledge of available platforms to conduct
TDM analytical assays in your lab
Laboratory requirements for accepting,
receiving and preparing samples
Laboratory requirements for conducting TDM
analytical assays
Evaluation and implementation of
commercial TDM analytical assays
Processes of designing and developing TDM
analytical assays
Processes of validating TDM analytical assays
Processes of controlling TDM analytical
assays, assay QC, maintenance, and training
Definition of detection and/or quantitation
ranges for TDM analytical assays
Laboratory standards for reporting TDM
analytic assay results
Technical supervision / lab management
Training & professional development of staff
members
Research to improve laboratory processes and
results
Fiscal operations of laboratory / laboratory
division
22. On a scale of 1 to 7, how experienced are you with immunoassays, mass spectrometry,
and HPLC-UV for TDM analytical assays?
(1 means “no experience” and 7 means “very experienced”)
Respondent Profile
13
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
Experience with IA, Mass Spec., and HPLC-
UV
1 2 3 4 5 6 7
Immunoassays
Mass spectrometry
HPLC-UV
B. PROCESS OF CONDUCTING TDM ANALYTICAL ASSAYS:
1. Does your lab specify a standard procedure for sample handling prior to arrival in the
laboratory?
# Standard Procedure Select One
1 No
2 Yes
3 Not sure
2. Which anticoagulant does your lab use or accept during sample acquisition?
Select all that apply
# Anticoagulant Cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 EDTA
2 Heparin
3 Citrate
4 None, use serum instead
5 Others, please specify:
__________
3. If your lab receives samples from outside entities for TDM analytical assays, what are the
acceptable shipping conditions?
Drop-down menu: “Acceptable,” “Not acceptable”
Respondent Profile
Sam. Acq. &
Sam. Acq. &
Sam. Acq. &
14
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
# Shipping Condition Cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Samples shipped at ambient
temperature, unlimited time
2 Samples can remain at ambient
temperature for up to 24 hours
3 Samples shipped refrigerated or
frozen
4 Ship at ambient temperature,
refrigerate or freeze upon receipt
5 No special conditions specified
4. What percentage of all samples received is rejected for TDM analytical assays for the
following reasons?
Select One
# Rejection Reason 0% 1-2% 3-5% > 5%
1 Requirements of minimal
sample volumes not met
2 Incorrect anticoagulant used
during sample acquisition
3 Samples clotted
4 Requirements of storage /
shipping temperatures not met
5 Incorrect matrix
6 Samples mislabeled
7 Incomplete documentation /
missing paperwork
8 Sample age specification not met
9 Others (please specify):
__________
Sam. Acq. &
15
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
5. What is the average elapsed time from sample receipt to sample preparation?
Select One
# Elapsed Time from Receipt to
Preparation
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Within 4 hours
2 Within 24 hours
3 Within 1 week
4 Within 2 weeks
5 More than 2 weeks
6. How are patient samples for TDM analytical assays stored upon receipt prior to
preparation?
Select One
# Storage Condition cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Ambient temperature
2 Refrigerated (0 – 4°C)
3 Frozen at -20°C
4 Frozen at -80°C
5 Others (please specify):
__________
7. Does your lab have a standard sample preparation procedure?
# Standard Procedure Select One
1 No
2 Yes, specified by manufacturers
3 Yes, developed by the lab
4 Not sure
Sam. Acq. &
Sam. Acq. &
Samp. Prep. & Ext.
16
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
8. In your lab, what is the typical batch size for patient samples for TDM analytical assays?
Select One
# Batch Size cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 1 – 10 samples
2 10 – 25
3 26 – 50
4 50 – 100
5 > 100
9. If applicable, what percentage of samples is resuspended using the following methods
prior to sample pretreatment or extraction?
# Resuspension Method Please assign percentage
(%)
1 Manual tube inverting
2 Vortexing
4 Mechanical tube rocker
5 Ultrasound
6 No resuspension performed
7 Others, please specify:
__________
10. Is there a standard dilution procedure in your lab?
Select One
# Standard Procedure cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 No standard dilution procedure
2 Yes, standard procedure for all
samples
3 Standard procedure exists for
samples that are outside the
linear range of assays
Samp. Prep. & Ext.
Samp. Prep. & Ext.
Samp. Prep. & Ext.
17
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
11. How does your lab perform sample pretreatment / extraction?
Select One
# Sample Pretreatment / Extraction cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Manual
2 Automated
3 Using online column extraction
(for mass spectrometry)
12. What sample precipitation / extraction solutions does your lab use?
Select One
# Pretreatment / Extraction cyclosporine tacrolimus sirolimus everolimus mycophenolate
Immunoassay
1 Methanol
2 Acetonitrile
3 Diethyl ether
4 Manufacturer proprietary
5 Others (please specify):
__________
Mass Spec. & HPLC-UV
6 ZnSO4 + methanol precipitation
7 ZnSO4 + acetonitrile
precipitation
8 Solid phase extraction
9 Liquid phase extraction
10 Others (please specify):
__________
Samp. Prep. & Ext.
Samp. Prep. & Ext.
18
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
13. Does your lab concentrate samples during sample precipitation / extraction? If so , what
method does your lab use?
Select One
# Concentration Method cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Never concentrate samples
2 Speed vacuum
3 Evaporation under nitrogen
4 Temperature elevation
5 Concentration on column
6 Others, please specify:
__________
14. What is the elapsed time from sample preparation to the start of the run?
Select One
# Elapsed Time from Preparation
to Run Start
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 < 1 hour
2 1 – 4 hours
3 4 – 8 hours
4 8 – 12 hours
5 12 – 24 hours
6 > 24 hours
Samp. Prep. & Ext.
Samp. Prep. & Ext.
19
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
15. What is the average run time for every batch?
Select One
# Average Run Time for Every
Batch
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Less than 1 hour
2 1 – 2 hours
3 2 – 4 hours
4 4 – 8 hours
5 8 – 24 hours
6 More than 24 hours
16. If samples are not tested immediately (< 1 hour until batch start) after pretreatment, are
samples stored in a temperature controlled manner?
Select One
# Samples Temperature
Controlled?
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 No
2 Yes, refrigerated (0 – 4°C)
3 Yes, frozen at -20°C
4 Yes, frozen at -80°C
17. How long does your lab retain the original blood sample?
Select One
# Retaining of Blood Sample cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 1 – 2 days
2 1 week
3 2 weeks
4 1 month
5 > 1 month
Samp. Prep. & Ext.
Samp. Prep. & Ext.
Samp. Prep. & Ext.
20
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
18. At what temperature does your lab retain the original blood sample?
Select One
# Retaining Temperature cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Ambient temperature
2 Refrigerated (0 – 4°C)
3 Frozen at -20°C
4 Frozen at -80°C
5 Others, please specify:
__________
19. Are the following equipment and materials used during TDM analytical assays regulated
by any standard procedure in your lab?
# Regulated by Standard Procedures? Yes No
1 Centrifuges (e.g. specifying temperature
and speed)
2 Types of pipettes
3 Types of pipette tips
4 Sample containers
5 Stock solutions
6 Chemical grade
20. Does your lab consistently use the same centrifuge each time an assay is performed for
an immunosuppressant drug?
# Same Centrifuge Each Time? Select One
1 No
2 Yes
Samp. Prep. & Ext.
Samp. Prep. & Ext.
Samp. Prep. & Ext.
21
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
21. If multiple centrifuges are used, on a scale of 1 to 7, how well are centrifuges controlled
for the following parameters during sample preparation?
(1 indicates “not at all controlled” and 7 indicates “extremely well controlled”)
# Parameter Not
Sure
1 2 3 4 5 6 7
1 Temperature
2 Speed (e.g. rpm)
3 Rotor diameter
4 g force
5 Others, please specify: __________
22. Are centrifuges serviced and verified on a regular basis?
On a regular basis?
# Centrifuge Yes No
1 Service
2 Verification
23. What types of pipettes does your lab use during the following steps of sample
preparation?
Select all that apply
# Type of Pipettes Transferring
blood sample
Adding protein
precipitation
solutions
Adding
internal
standards
Transfer
extracts to
instruments
1 Manual single channel fixed
volumes pipettes
2 Manual single channel variable
volume pipettes (also known as
mechanical, adjustable or digital)
3 Manual multichannel variable
volume pipettes
4 Manual single channel positive
displacement pipettes
Samp. Prep. & Ext.
Samp. Prep. & Ext.
Samp. Prep. & Ext.
22
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
5 Electronic single channel
variable volume pipettes
6 Electronic multichannel variable
volume pipettes
7 Robotic pipettes
8 Others, please specify:
__________
24. How often does your lab calibrate pipettes?
# Frequency Select One
1 Every 3 months or more frequent
2 Every 6 months
3 Every 12 months
4 Once in > 1 year
5 Never
25. Does your lab use barrier pipette tips for TDM analytical assays?
# Use of Barrier Pipette Tips Select One
1 No
2 Yes, for some samples
3 Yes, for most samples
4 Yes, for all samples
26. Does your lab assign expiration dates to stock solutions?
# Expiration Date Select One
1 No
2 Yes
3 Not sure
Samp. Prep. & Ext.
Samp. Prep. & Ext.
Samp. Prep. & Ext.
23
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
27. What grade of chemicals does your lab use for TDM analytical assays?
Select One
# Chemical Grade For Solvents for
Sample
Preparation
For Reference
Materials
(Mass Spec. &
HPLC-UV) For
HPLC
1 Reagent grade
2 HPLC grade
3 Spectroscopy grade
4 Others (please specify):
__________
28. What quality of water does your lab use for TDM analytical assays?
Select One
# Water Quality For Solvents for
Sample
Preparation
For Reference
Materials
(Mass Spec. &
HPLC-UV) For
HPLC
1 Filtered only
2 Filtered and de-ionized
in house
3 Milli-Q (filtered and de-
ionized)
4 HPLC-grade
5 Double-distilled
6 Others (please specify):
__________
Samp. Prep. & Ext.
Samp. Prep. & Ext.
24
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
29. How are patient samples introduced to mass spectrometers?
Mass Spec.
# Introduction of Samples Select One
1 Flow injection
2 Standard HPLC
3 Ultra-performance HPLC (U-
HPLC)
4 Others, please specify:
__________
30. What type of columns in chromatography is used in your lab for TDM analytical assays?
Mass Spec. & HPLC-UV
# Column Please select one or specify
1 Size (e.g. length &
diameter)
Please specify length: __________
Please specify diameter: __________
2 Material C8 C18 Others, please
specify:
__________
3 Extended pH Yes No
4 Composition Silica gel Synthetic
materials
Others, please
specify:
__________
5 End-capped Yes No
6 Particle size Please specify: __________
Conduct of Assays
Conduct of Assays
25
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
31. What is the composition of the mobile phase in chromatography used in your lab for
TDM analytical assays?
Mass Spec. & HPLC-UV Select all that apply
# Composition of the Mobile
Phase
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Methanol
2 Acetonitrile
3 Water, pH not adjusted
4 Water, pH adjusted to 3 – 5
5 Water, pH adjusted to 5 – 7
6 Water, pH adjusted to 7 – 8
7 Water, pH adjusted to > 8
8 Others, please specify:
__________
32. At what (column) temperature does your lab run the mobile phase in chromatography?
Mass Spec. & HPLC-UV Select One
# Column Temperature cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Below room temperature
2 Room temperature, uncontrolled
3 Room temperature, controlled
4 Between room temperature and
40°C
5 40 – 65°C
6 Others, please specify:
__________
Conduct of Assays
Conduct of Assays
26
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
33. What elution method in chromatography does your lab use for TDM analytical assays?
Mass Spec. & HPLC-UV Select One
# Elution Method cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Isocratic
2 Gradient
3 No chromatography used
34. What ion source does your lab use for mass spectrometry (for the primary / prevalent
instrument / system in your lab)?
Mass Spec. Select One
# Ion Source cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Electrospray ionization
2 Atmospheric pressure chemical
ionization (APCI)
3 Others, please specify:
__________
35. What type of mass spectrometer does your lab use (for the primary / prevalent
instrument / system in your lab)?
Mass Spec. Select One
# Mass Analyzer cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Single stage quadrupole
2 Triple stage quadrupole
3 Ion trap
4 Others, please specify:
__________
Conduct of Assays
Conduct of Assays
Conduct of Assays
27
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
36. (MASS SPEC & HPLC-UV) What internal reference standards are used for each
immunosuppressant drug?
Mass Spectrometry Select One
# Internal Standard cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Ascomycin
2 Cyclosporin D (CsD)
3 Isotope labeled cyclosporin A
(CsA)
4 Isotope labeled tacrolimus
5 Isotope labeled sirolimus
6 Isotope labeled everolimus
7 Isotope labeled mycophenolate
8 Others, please specify:
__________
37. What ion or ion transitions are monitored to quantify each immunosuppressant drug?
Mass Spectrometry Please specify
# Ion or Ion Transitions cyclosporine tacrolimus sirolimus everolimus mycophenolate
Examples: 1224.9/1112.6 826.6/616.2 936.8/409.2 980.8/389.4 343.3/229.1
38. How many ion transitions (quantifier and qualifier ions) are monitored for each
immunosuppressant drug?
Mass Spectrometry Please specify
# # of Ion Transitions Monitored cyclosporine tacrolimus sirolimus everolimus mycophenolate
Conduct of Assays
Conduct of Assays
Conduct of Assays
28
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
39. When weighing reference materials (e.g. internal standards, calibrators, and controls),
does your lab compensate for drug impurities or water content (e.g. sirolimus is almost
never > 98% pure)?
Select One
# Impurity Compensation cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 No
2 Yes
40. How does your lab store stock solutions containing internal standards?
Mass Spectrometry Select One
# Storage Temperature cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Ambient temperature
2 Refrigerated (0 – 4°C)
3 Frozen at -20°C
4 Frozen at -80°C
41. What is the shelf life of the stock solutions containing internal standards under the above
storage condition in your lab?
Mass Spec.
# Storage Time Select One
1 < 6 hours
2 < 12 hours
3 < 24 hours
4 < 1 week
5 Batched and stored in
refrigerators
6 Others, please specify:
__________
Conduct of Assays
Conduct of Assays
Conduct of Assays
29
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
42. Does your lab use the same stock solutions when preparing controls and calibrators?
# Same Stock Solutions Select One
1 No
2 Yes
43. When testing multiple immunosuppressant drugs, does your lab test them separately or
run multi-analyte assays?
Mass Spectrometry Select One
# Testing of Multiple Analytes cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Test individually
2 Multi-analyte assay
44. Does your lab run immunoassays for patient samples in batch or random access mode?
Immunoassay
# Batch or Random Access Select all that apply
1 Batch, please specify how many
times per day: __________
2 Upon receipt (random access
mode)
Conduct of Assays
Conduct of Assays
Conduct of Assays
30
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
45. Does your lab purchase commercial calibrators (e.g. from assay kits) or prepare them in
house? If prepared in house, are those calibrators made from whole blood?
Select all that apply
# Source of Calibrators cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Commercial calibrators
2 Prepared in house and from
whole blood
3 Prepared in house, but not from
whole blood
4 Others, please specify:
__________
46. Does your lab purchase commercial controls (e.g. from assay kits) or prepare them in
house? If prepared in house, are those controls made from whole blood?
Select all that apply
# Source of Controls cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Commercial controls
2 Prepared in house and from
whole blood
3 Prepared in house, but not from
whole blood
4 Others, please specify:
__________
47. How are calibrators and controls prepared in your lab?
# Preparation of Calibrators &
Controls
Select One
1 From ready-to-use calibrator and
control sets
2 Dilution from stock solutions
QA / QC
QA / QC
QA / QC
31
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
48. How is dilution performed for calibrators?
# Dilution Select One
1 Serial dilution
2 Direct or individual dilution
49. Are new lots of quality control samples, calibrators, and internal standards tested against
previous lots (qualified)?
# Qualification of Controls,
Calibrators, & Internal Standards
Select One
1 No qualification
2 Yes, we qualify
3 Not sure
50. How many different calibrators does your lab run for a typical calibration curve?
Select One
# Calibrators cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 1
2 2 – 3
3 4 – 6
4 7 – 8
5 > 8
QA / QC
QA / QC
QA / QC
32
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
51. How often does your lab run calibrators?
Select One
# Calibrator Frequency cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Within each batch
2 2 – 3 times a day
3 Once per day
4 Once per week
5 Others, please specify:
__________
52. How many different quality control samples does your lab run?
# QC Samples Select One
1 0
2 1
3 2
4 3
5 > 3
53. How often does your lab run quality control samples?
Select One
# QC sample Frequency cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Within each batch
2 2 – 3 times a day
3 Once per day
4 Once per week
5 Others, please specify:
__________
QA / QC
QA / QC
QA / QC
33
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
54. How does your lab run controls and calibrators?
Select One
# Manner cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 In singlicate
2 In duplicate
3 In triplicate
55. What type of quality control samples is used for each immunosuppressant drug?
Select One
# Type of QC Samples cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Artificial plasma, serum or
whole blood
2 Commercial plasma or whole
blood
3 Prepared in house
4 Others, please specify:
__________
56. Are calibrators and controls stored on or off board on the instrument in your lab?
Immunoassay Select One
# Storage of Calibrators &
Controls
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 On board
2 Off board
QA / QC
QA / QC
QA / QC
34
Sam. Acq. & Receipt Samp. Prep. & Ext. Conduct of Assays QA / QC
57. Are reagents stored on or off board on the instrument in your lab?
Immunoassay Select One
# Storage of Reagents cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 On board
2 Off board
58. What are the lower limits of detection (ng / mL) for the assays used in your lab?
Please specify
# LLOD cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 ng / mL
59. What are the quantitation ranges (ng / mL) for the five immunosuppressant drugs?
Please specify
# Quantitation Range cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Upper limit of quantitation (ng /
mL)
2 Lower limit of quantitation (ng /
mL)
QA / QC
QA / QC
QA / QC
35
Assay Development
C. TDM ANALYTICAL ASSAY DEVELOPMENT:
1. Who in your lab is responsible for determining the detection and quantitation ranges of
the assays?
# Assay Designer Select all that apply
1 Lab Director / Medical Director
2 Lab Manager / Supervisor
3 Lab technician
4 Research scientist
5 Clinical physician
6 Other, please specify: __________
2. How is the lower limit of detection determined?
# Determination of LLOD Select all that apply
1 Signal to noise: 3:1
2 Others, please specify: __________
3. During initial assay validation, how are the lower and upper limits of the quantitation
range determined?
# Limit of Quantitation Please specify
1 Lower limit of quantitation (LLOQ)
2 Upper limit of quantitation
Assay Development
Assay Development
Assay Development
36
Assay Development
4. How are the analytical ranges determined for the five immunosuppressant drugs?
Select One
# Determination of Analytical
Ranges
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 LLOQ and upper limit of
quantitation
2 Clinical considerations
3 Others, please specify:
__________
5. Based on the ranges, where does your lab place calibrators?
# Placement of Calibrators Select all that apply
1 At the extremes of the detection
range
2 At the extremes of the
quantitation range
3 Between the extremes of the
detection & quantitation ranges
6. What are the acceptance criteria for calibration curve?
# Acceptance Criteria for
Calibration Equation
Select all that apply
1 Number of outliers
2 Correlation co-efficient ≥ 0.999
3 Intercept
4 Deviation from nominal value
has to be within ±15% for at least
2/3 of the calibrators
7. How does your lab establish therapeutic target ranges for immunosuppressant drugs?
Assay Development
Assay Development
Assay Development
37
Assay Development
Select One
# Therapeutic Target Ranges cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Regulatory agency (e.g. FDA)
approved reference ranges
2 Published reference ranges
3 Established by the lab
4 Others, please specify:
__________
Assay Development
38
Assay Validation
D. TDM ANALYTICAL ASSAY VALIDATION:
1. Which regulatory guidance does your lab primarily follow for TDM analytical assay
validation?
# Guidance for Assay Validation Select One
1 College of American Pathologists
(CAP)
2 Regulatory agency (e.g. FDA)
guidance
3 Clinical Laboratory & Standards
Institute
4 Applicable ISO Standard
5 Others, please specify:
__________
2. What parameters or analyses does your lab validate for commercial and lab developed
assays?
Select all that apply
# Parameters or Analyses Commercial
Assays
Lab
Developed
Assays
1 Specificity
2 Lower limit of detection (LLOD)
3 Upper limit of detection
4 Lower limit of quantitation (LLOQ)
5 Upper limit of quantitation
6 Lower limit of blank (LLOB)
7 Range of linear response
8 Within-run imprecision
9 Within-day imprecision
10 Day-to-day imprecision
11 Accuracy
12 Linearity
13 Matrix interferences
14 Matrix effects (e.g. ion suppression)
15 Extraction recovery
Assay Validation
Assay Validation
39
Assay Validation
16 Carry over
17 Dilution integrity
18 Partial volume verification
19 Stock solution stability
20 Extracted sample (auto-sampler) stability
21 Freeze thaw cycle stability
22 Long-term stability
23 Cross-validation with other laboratories
3. How is instrument performance (operating qualification) ensured?
# Instrument Performance Select all that apply
1 Not performed
2 OQ repeated after major repair
3 Scheduled requalification
4 Not re-qualified
4. When determining imprecision, how many replicates per run does your lab run? How
many runs per day? How many days in total?
Please specify
# For Imprecision Within-run
Imprecision
Within-day
Imprecision
Day-to-day
Imprecision
1 # of replicates per run
2 # of runs per day
3 # of days for imprecision runs in
total
Assay Validation
Assay Validation
40
Assay Validation
5. What level of within-run imprecision (% CV) is considered to be acceptable for quality
control samples with concentrations near the middle of the standard curve?
Select One
# Level of Within-run Imprecision
(% CV)
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 < 5%
2 5-10%
3 10-15%
4 15-20%
5 > 20%
6. What level of within-day imprecision (% CV) is considered to be acceptable for quality
control samples with concentrations near the middle of the standard curve?
Select One
# Level of Within-day Imprecision
(% CV)
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 < 5%
2 5-10%
3 10-15%
4 15-20%
5 > 20%
Assay Validation
Assay Validation
41
Assay Validation
7. What level of day-to-day imprecision (% CV) is considered to be acceptable for quality
control samples with concentrations near the middle of the standard curve?
Select One
# Level of Day-to-day Imprecision
(% CV)
cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 < 5%
2 5-10%
3 10-15%
4 15-20%
5 > 20%
8. How many patient samples does your lab use during method comparison (i.e. cross-
validation)?
# # of Patient Samples Select One
1 None
2 1-25
3 25-50
4 50-100
5 > 100
9. How are method comparisons conducted in your lab?
# Cross-validation Select all that apply
1 No method comparison
conducted
2 Cross-validate within the lab
3 Cross-validate across centers
4 Cross-validate against other
methods (e.g. immunoassays
cross-validated against mass
spectrometry, or vice versa)
Assay Validation
Assay Validation
Assay Validation
42
Assay Validation
10. Under what situations would your lab conduct partial validation for TDM analytical
assays?
# Partial Validation Situation Select all that apply
1 Addition of new types of
transplant samples (e.g.
measuring kidney transplant
samples using assays validated
for liver transplant samples)
2 Method transfer to new
instruments
3 Instrument repair
4 Method modification (e.g.
reagent changes, parameter
optimization)
5 Proficiency test failure
6 In response to corrective action
7 Others, please specify:
__________
11. Under what situations would your lab conduct re-validation for TDM analytical assays?
# Re-validation Situation Select all that apply
1 Method modification
2 Acquisition of new instruments
3 Proficiency test failure
4 In response to other corrective
measures
5 Others, please specify:
__________
Assay Validation
Assay Validation
43
Assay Validation
12. How often does your lab conduct full re-validation for TDM analytical assays?
# Frequency of Re-validation Select One
1 Once in a year
2 Once in 2 years
3 Once in 5 years
4 Once in 10 years
5 Never conducted re-validation
13. When was the last time your lab conducted re-validation for TDM analytical assays?
# Last Time Select One
1 3 months ago
2 6 months ago
3 1 year ago
4 More than 1 year ago
5 More than 1 year ago, when the
assay was first implemented
6 Never validated
Assay Validation
Assay Validation
44
Assay Implement.
E. TDM ANALYTICAL ASSAY IMPLEMENTATION:
1. What level of training does lab personnel receive before conducting TDM analytical
assays?
# Level of Training Select all that apply
1 Direct observation of patient test
performance/employee duties
2 Direct observation of
performance of instrument
maintenance and function checks
3 Observation for compliance with
safety protocols
4 Assessment/evaluation of
problem solving skills
5 Assessment of test performance
6 Monitoring, recording and
reporting of test results
7 Review of intermediate test
results and work product records
for compliance with standard
operating procedures and
applicable work load limits
2. Who provides training for TDM analytical assays?
# Trainer Select all that apply
1 Assay developer
2 Assay conductor
3 Assay supervisor
4 Lab director
5 Training technologists /
education specialists
6 Others, please specify:
__________
Assay Implement.
Assay Implement.
45
Assay Implement.
3. How many years of TDM analytical assay experience does the trainer have?
# Years of TDM Assay Experience Select One
1 < 2 years
2 3 – 5 years
3 6 – 10 years
4 > 10 years
4. How often does your lab provide refresher training or re-training?
# Frequency of Re-training Select One
1 Once in a month
2 Once in a year
3 As necessary
4 In response to corrective actions
only
5 No policy in place
Assay Implement.
Assay Implement.
46
Proficiency Test
F. TDM ANALYTICAL ASSAY CONTROL / QC:
1. By whom are the target values (means) and acceptable ranges of QC samples determined
(e.g. by manufacturer vs. by laboratory)?
# Determined By Select One
1 Manufacturer
2 Lab
2. When quality control samples are outside the acceptable ranges, what actions are taken
prior to re-running of assays?
# Actions Taken Select all that apply
1 Perform maintenance
2 Test system suitability
3 Recalibrate
4 Pass internal QCs
5 Pass external QCs
6 Pass stored proficiency testing
samples
7 Successful cross-validation with a
reference laboratory
8 Partial validation of the assays as
deemed fit-for-purpose
3. What samples does your lab use to monitor imprecision?
Select all that apply
# Samples Used cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Internal QC samples
2 External QC samples
3 Pooled patient samples
4 Proficiency test samples
5 Others, please specify:
__________
Control / QC
Control / QC
Control / QC
47
Proficiency Test
4. What samples does your lab use to monitor long-term quality of assay performance?
# Samples Used Select all that apply
1 Internal QC samples
2 External QC samples
3 Pooled patient samples
4 Proficiency test samples
5 Others, please specify:
__________
5. What criteria are used to confirm and monitor long-term stability and validity of assays
in your lab?
# QC Criteria Select all that apply
1 Linearity
2 Precision
3 Accuracy
4 Sensitivity
5 Specificity
6. How does your lab test system suitability?
(System suitability: check for readiness of mass spectrometry system)
Mass Spec.
# Procedure of Testing System
Suitability
Select all that apply
1 Neat blank (e.g. methanol)
2 Neat standard at LLOQ
3 Neat standard at upper limit of
quantitation
4 Additional neat standard
between LLOQ and upper limit
of quantitation
5 Carry over control
Control / QC
Control / QC
Control / QC
48
Proficiency Test
7. How often does your lab test system suitability?
Mass Spec.
# Frequency of System Suitability
Testing
Select all that apply
1 Every batch
2 Daily
3 Weekly
4 Monthly
5 Twice in a year
6 Annually
7 After each maintenance
8 After repeated calibrator / control
failures
9 Not done at all
8. What is the preventive maintenance schedule of instruments in your lab?
# Preventive Maintenance Schedule Select One
Water filtration system
1 Weekly
2 Monthly
3 Twice in a year
4 Annually
5 No scheduled preventive
maintenance
Immunoassay
# Preventive Maintenance Schedule Select One
Immunoassay analyzers
1 Weekly
2 Monthly
3 Twice in a year
4 Annually
5 No scheduled preventive
maintenance
Control / QC
Control / QC
49
Proficiency Test
Mass Spec. & HPLC-UV
# Preventive Maintenance Schedule Select One
HPLC valves and filters
1 Weekly
2 Monthly
3 Not at all
Mass Spec.
# Preventive Maintenance Schedule Select One
Mass spectrometer
1 Twice in a year
2 Annually
3 As required
4 As recommended by
manufacturer
5 No scheduled preventive
maintenance
9. Who carries out preventive maintenance in your lab?
# Preventive Maintenance Select One
1 By laboratory personnel
2 Through service contract with
manufacturer or equally qualified
outside provider
10. Does your lab use multiple instruments (e.g. due to high-volume demand or as a
backup)? If yes, are these instruments cross-validated?
# Multiple Instruments Select One
1 Never use
2 Yes, but NOT cross-validated
3 Yes, and cross-validated
Control / QC
Control / QC
50
Proficiency Test
11. How often are internal QA audits (including laboratory, in-process, assay performance
and documentation) conducted?
# QC Audits Select One
1 Every month
2 Every 3 months
3 Every 6 months
4 Every year
5 Never
12. Is there a long-term tracking procedure for assay performance (e.g. based on QC
samples) in place in your lab?
# Long-Term Tracking Procedure Select One
1 No
2 Yes
13. Is there any other policy for quality control / quality improvement that your lab adheres
to?
# Policy for QC Select One
1 No other policy
2 Additional policy exists (please
specify: __________)
Control / QC
Control / QC
Control / QC
51
Proficiency Test
G. PROFICIENCY TEST:
1. What TDM analytical assay proficiency test program or cross-validation scheme does
your lab participate in for the following immunosuppressant drugs?
Select all that apply
# Proficiency Tests cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 College of American
Pathologists (CAP) proficiency
programs
2 Analytical Services International
(ASI) proficiency programs
3 Other proficiency programs,
please specify: __________
4 External cross-validation
5 No proficiency program or
external cross-validation
2. How often does your lab conduct periodic cross-validation / proficiency sample runs?
Select One
# Frequency of Proficiency Runs cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 Every month
2 Every 3 months
3 Every 6 months
4 Once in a year
5 Once in a couple of years
6 Never participated in cross-
validation or proficiency tests
Proficiency Test
Proficiency Test
52
Proficiency Test
3. Does your lab run proficiency test samples on all of your instruments?
# Proficiency Tests Select One
1 No
2 Yes
4. What corrective measures does your lab take when proficiency tests are out of range?
# Actions Taken Select all that apply
1 Perform maintenance
2 Test system suitability
3 Recalibrate
4 Pass internal QCs
5 Pass external QCs
6 Pass stored proficiency testing
samples
7 Successful cross-validation with a
reference laboratory
8 Partial validation of the assays as
deemed fit-for-purpose
5. Is there a re-test policy for aberrant samples (e.g. samples that fall out of the reference
ranges, or the ones identified by clinicians)?
# Re-test Select One
1 No
2 Yes
3 Not sure
Proficiency Test
Proficiency Test
Proficiency Test
53
Hypotheses
H. HYPOTHESIS FOR INTER-LAB VARIABILITY OF TDM ANALYTICAL ASSAYS:
1. How much do you agree with the following statements?
(1 means “not at all agree” and 7 means “very much agree”)
Statement 1 2 3 4 5 6 7
Current inter-lab (i.e. among labs) variability
of TDM analytical assays is a huge issue.
Current intra-lab (i.e. within a lab) variability
of TDM analytical assays is a huge issue.
A commercially available assay is more
reliable than a lab developed test.
I feel our quantitation ranges are adequate at
addressing clinical needs.
I feel able to address clinicians’ concerns
around interpretation of TDM analytical assay
results and associated dosing / titration of
immunosuppressant drugs.
2. Please rank immunoassay, mass spectrometry, and HPLC-UV as a TDM analytical assay
method for immunosuppressant drugs across the following parameters.
Parameter Immunoassay Mass Spectrometry HPLC-UV
Sensitivity
Drop-down menu for each column: “Best,” “Good,” “Not as
good as the other two.”
Specificity
Linearity
Accuracy
Precision
Technical difficulty Drop-down menu for each column: “Most difficult,”
“Difficult,” “Not as difficult as the other two.”
Cost effectiveness Drop-down menu for each column: “Best,” “Good,” “Not as
good as the other two.” Clinical decisions
Result turnaround time
Impact on lab work flow Drop-down menu for each column: “Strong impact,” “Some
impact,” “Not as impactful as the other two.” Impact on lab infrastructure
Hypotheses
Hypotheses
54
Hypotheses
3. Do you think there is a significant bias problem across laboratories?
Select One
# Significant Bias cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 No
2 Yes
3 Not sure
4. Does your lab plan to switch to another TDM analytical assay method for the following
immunosuppressant drugs?
Select One
# Switching Decision cyclosporine tacrolimus sirolimus everolimus mycophenolate
1 No switch planned
2 Switch to immunoassay
3 Switch to mass spectrometry
4 Switch to HPLC-UV
5 Not sure
5. To what extent do you believe the following factors contribute to inter-lab variability of
TDM analytical assays for immunosuppressant drugs?
(1 means “not at all” and 7 means “very much”)
# Contributor 1 2 3 4 5 6 7
1 Sample collection
2 Sample shipping & storage
3 Suboptimal sample preparation
(e.g. extraction)
4 Suboptimal assay design
5 Technician error
6 Inappropriate controls,
calibrators, internal reference
standards
7 Reagent stability
Hypotheses
Hypotheses
Hypotheses
55
Hypotheses
8 Inappropriate internal standard
9 Instrument maintenance
10 Multiple instruments
11 Use of lab developed tests vs.
commercially available ones
12 Insufficient assay performance
tracking
13 Insufficient personnel
qualification or training
14 Others, please specify:
__________