HemocytometerFrom Wikipedia, the free encyclopediaThis article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009)A hemocytometer. The two semi-reflective rectangles are the counting chambers.Load a chamberHemocytometer grid see table!The hemocytometer is a device used to count cells. "t was originally designed for the counting of blood cells.The hemocytometer was invented by Louis-#harles $alasse% and consists of a thick glass microscope slide with a rectangular indentation that creates a chamber. This chamber is engraved with a laser-etched grid of perpendicular lines. The device is carefully crafted so that the area bounded by the lines isknown, and the depth of the chamber is also known. "t is therefore possible to count the number of cells or particles in a specific volume of fluid, and thereby calculate the concentration of cells in the fluid overall.Contents&hide' ()rinciples *+sage ,-e.uirements /0pplications 1-eferences 234ternal linksPrinciples&edit'The gridded area of the hemocytometer consists of several ( 4 ( mm ( mm*! s.uares. These are subdivided in , directions5 6.*1 4 6.*1 mm 6.62*1 mm*!, 6.*1 4 6.*6 mm 6.61 mm*! and 6.*6 4 6.*6 mm 6.6/ mm*!. The centrals.uare is further subdivided into 6.61 4 6.61 mm 6.66*1 mm*! s.uares.The raised edges of the hemocytometer hold the coverslip 6.( mm off the marked grid, giving each s.uare a defined volume see figure on the right!.&('Dimensions Area Volume at 0.1 mm depth1 x 1 mm 1 mm2100 nL0.25 x 0.25 mm 0.0625 mm26.25 nL0.25 x 0.20 mm 0.05 mm25 nL0.20 x 0.20 mm 0.0 mm2 nL0.05 x 0.05 mm 0.0025 mm20.25 nLUsage&edit'To use the hemocytometer, first make sure that the special coverslip provided with the counting chamberis properly positioned on the surface of the counting chamber. When the two glass surfaces are in propercontact 7ewton8s rings can be observed. "f so, the cell suspension is applied to the edge of the coverslip to be sucked into the void by capillary action which completely fills the chamber with the sample. The number of cells in the chamber can be determined by direct counting using a microscope, and visually distinguishable cells can be differentially counted. The number of cells in the chamber is used to calculate the concentration or density of the cells in the mi4ture the sample comes from. "t is the number of cells in the chamber divided by the chamber8s volume, which is known from the start, taking account ofany dilutions and counting shortcuts9 &*'where the volume of the diluted sample is the volume of the sample after dilution and the volume of the original mi4ture in the sample is the volume of the actual cell suspension undiluted. For e4ample, if the volume of the original mi4ture was *6:L and it was diluted once by adding *6:L dilutant!, then the second term in parentheses is /6:L;*6:L. The volume of the s.uares counted is the one shown in the table at the top, depending on the si%e see figure on the right!. The number of cells counted is the sum of all cells counted across s.uares in one chamber. The proportion of the cells counted applies if not all inner s.uares within a set s.uare are counted i.e., if only / out of the *6 in a corner s.uare are counted,then this term will e.ual 6.*!.The parts of the hemocytometer as viewed from the side! are identified.For most applications, the four large corner s.uares are only used. The cells that are on or touching the top and left lines are counted, but the ones on or touching the right or bottom lines are ignored.&,'Requirements&edit'3mpty hemocytometer grid at (664 power. The original suspension must be mi4ed thoroughly before taking a sample. This ensures the sample is representative, and not herach 3$, >trober W. Current Protocols in Immunology 5. +>09 @ohn Wiley B >ons. p. 0.*0.(.doi9(6.(66*;6/C((/*C,1.ima6,as*(./. Jump up ^ ?$easuring cell si%e with a hemocytometer?.External links&edit' Dnline e4ercise - Eeast counts in 7eubauer improved or Thoma counting chambers Hemocytometer calculator online#ategories9 Laboratory e.uipment 7eubauer chamber7avigation menu #reate account Log in 0rticle Talk -ead 3dit Fiew history $ain page #ontents Featured content #urrent events -andom article Aonate to Wikipedia Wikimedia >hop"nteraction Help 0bout Wikipedia #ommunity portal -ecent changes #ontact pageTools What links here -elated changes +pload file >pecial pages )ermanent link )age information Wikidata item #ite this page)rint;e4port #reate a book Aownload as )AF )rintable versionLanguages GHIJKLM Aeutsch 3spaNol FranOais =ahasa "ndonesia "taliano )olski PQRRSTU3dit links This page was last modified on (V >eptember *6(/ at (19(6. Te4t is available under the #reative #ommons 0ttribution->hare0like License5 additional terms may apply. =y using this site, you agree to the Terms of +se and )rivacy )olicy. WikipediaW is a registered trademark of the Wikimedia Foundation, "nc., a non-profit organi%ation. )rivacy policy 0bout Wikipedia Aisclaimers #ontact Wikipedia Aevelopers $obile viewXoHemoglobin variants are a part of the normal embryonic and fetal development, but may also be pathologic mutant forms of hemoglobin in a population, caused by variations in genetics. >ome well-known hemoglobin variants such as sickle-cell anemia are responsible for diseases, and are considered hemoglobinopathies. Dther variants cause no detectable pathology, and are thus considered non-pathological variants.&1/'&11'"n the embryo9 Xower ( Y*Z*! Xower * [*Z*! )A= (0\W! Hemoglobin )ortland " Y*]*! Hemoglobin )ortland "" Y*^*!."n the fetus9 Hemoglobin F [*]*! )A= (FAH!.0fter birth9 Hemoglobin 0 [*^*! )A= (=_6! ` The most common with a normal amount over \1a Hemoglobin 0* [*b*! ` b chain synthesis begins late in the third trimester and, in adults, it has a normal range of (.1`,.1a Hemoglobin F [*]*! ` "n adults Hemoglobin F is restricted to a limited population of red cells called F-cells. However, the level of Hb F can be elevated in persons with sickle-cell disease and beta-thalassemia.Xene e4pression of hemoglobin before and after birth. 0lso identifies the types of cells and organs in which the gene e4pression data on Wood W.G., (\C2!. Br. Med. Bull. 32, 282.!Fariant forms that cause disease9 Hemoglobin A-)un [*^>*! ` 0 variant form of hemoglobin found in people with sickle cell disease. There is a variation in the ^-chain gene, causing a change in the properties of hemoglobin, which results in sickling of red blood cells. Hemoglobin # [*^#*! ` 0nother variant due to a variation in the ^-chain gene. This variant causesa mild chronichemolytic anemia. Hemoglobin 3 [*^3*! ` 0nother variant due to a variation in the ^-chain gene. This variant causesa mild chronichemolytic anemia. Hemoglobin 0> ` 0 hetero%ygous form causing >ickle cell trait with one adult gene and one sicklecell diseasegene Hemoglobin ># disease ` 0 compound hetero%ygous form with one sickle gene and another encodingHemoglobin #.