tools and techniques dna fingerprinting. intoducing the microliter! a tiny amounta millionth of a...
DESCRIPTION
The TOOLS DNA Fingerprinting makes use of tools that can work with incredibly SMALL volumes We only need a very small sample of DNA We can run hundreds or thousands of samples at once in small spaces We can be INCREDIBLY accurate and precise We can use robotic assistance to run the full analysisTRANSCRIPT
TOOLS AND TECHNIQUES
DNA Fingerprinting
Intoducing the microLiter!
A TINY amount…a millionth of a LiterVery difficult to measure because it is SOOO
smallIncredibly accurate when measured correctly
Tools that measure these amounts are therefore INCREDIBLY expensive…be VERY careful with them!!!
If a milliliter (mL) is 1/1000 of a Liter… A microliter (μl) is 1/1000 of a millileter (mL) The greek letter “mu” is used to represent micro (μ)
Let’s PRACTICE Work through the second page of the packet
“DNA Fingerprinting – Practice Worksheet”
The TOOLS
DNA Fingerprinting makes use of tools that can work with incredibly SMALL volumes We only need a very small sample of DNA We can run hundreds or thousands of samples at once
in small spaces We can be INCREDIBLY accurate and precise We can use robotic assistance to run the full analysis
The Micropipette
Are like a normal pipette…but better
They can hold incredibly small amounts of liquid with incredibly high accuracy and precision This makes them VERY
expensive!!!Two types that we will use:
P20: Can hold up to 20 μl P200: Can hold up to 200 μl
Draw and label a picture to refer back to:
Setting the Micropipette
Each micropipette has a dial for its particular volume maximum NEVER set the dial above the MAXIMUM listed, this
will damage the micropipette For a p20…NEVER set above 20
The three numbers represent the three place values Starting with the largest POSSIBLE place value
Let’s PRACTICE with the second half of practice worksheet
Techniques for Using Tips
NEVER TILT THE PIPETTE!!!NEVER USE A NAKED PIPETTE!!!
We use tips to hold liquid, not the pipette itself Liquids can actually damage (very severely) the internal parts
To pick up a tip, push the pipette into the tip holder ALWAYS keep the tip box COVERED This keeps out contaminants
After using ANY liquid, we will switch tips This will also help minimize the risk of contamination through
mixing of samplesTo eject a tip, push down on the SIDE button
This is attached to the metal rod that will push down on the tip Always eject tips into a WASTE BIN
Techniques for using a Micropipette
Push the PLUNGER to the FIRST Stop DO NOT GO FURTHER THAN THE FIRST STOP We must create a vacuum in order to pick up liquid
While holding it down, insert the tip into your liquid DO NOT LET GO UNTIL YOU ARE IN LIQUID This will pick up air, not the liquid
Release the plunger to pick up the liquidTo eject, move the tip into the desired container
Hold the tip against the inside surface of the container you wish to eject into
Push the PLUNGER to the SECOND Stop to eject ALL liquidLet’s practice!
Get a pipette each and practice picking up and ejecting a tip, and pushing the plunger to the FIRST and SECOND stop
Using the microcentrifuge
NEVER LOAD IT SIDEWAYS Like a washing/drying machine, it will spin out of
control and potentially breakALWAYS balance the load
In a 6-holder, this means you can load… NOT One Two Three Four NOT Five Six
Balance the epitubes in the rotor
Let’s practice!!!
Do activity One and Two on the second instructional handout Answer the first two questions by converting Answer questions 3 and 4: the “Lab Observations”
We will discuss and answer remaining questions after returning from break