Editing Automated analyser (section)

==Hematology analysers==
{{main|Hematology analyzer}}
These are used to perform [[complete blood count]]s, [[erythrocyte sedimentation rate]]s (ESRs), or [[coagulation]] tests.

===Cell counters===
{{see also|Complete blood count|White blood cell differential}}
Automated cell counters sample the blood, and quantify, classify, and describe cell populations using both electrical and optical techniques.
Electrical analysis involves passing a dilute solution of the blood through an aperture across which an electrical current is flowing. The passage of cells through the current changes the [[Electrical impedance|impedance]] between the terminals (the [[Coulter principle]]).<ref>{{cite web|url=http://www.beckman.com/coultercounter/homepage_tech_coulter_principle.jsp |title=CoulterCounter.com - the Coulter Principle |accessdate=2007-08-26 |url-status=dead |archiveurl=https://web.archive.org/web/20070928015537/http://www.beckman.com/coultercounter/homepage_tech_coulter_principle.jsp |archivedate=2007-09-28 }}</ref> A lytic reagent is added to the blood solution to selectively lyse the [[Red blood cell|red cells]] (RBCs), leaving only [[White blood cell|white cells]] (WBCs), and [[platelets]] intact. Then the solution is passed through a second detector. This allows the counts of RBCs, WBCs, and platelets to be obtained. The platelet count is easily separated from the WBC count by the smaller impedance spikes they produce in the detector due to their lower cell volumes.

Optical detection may be utilised to gain a differential count of the populations of white cell types. A dilute suspension of cells is passed through a flow cell, which passes cells one at a time through a capillary tube past a laser beam. The reflectance, transmission and scattering of light from each cell is analysed by sophisticated software giving a numerical representation of the likely overall distribution of cell populations.

Some of the latest hematology instruments may report [[Cell Population Data]] that consist in [[Leukocyte]] morphological information that may be used for flagging [[Cell (biology)|Cell]]  abnormalities that trigger the suspect of some [[diseases]].

[[Reticulocyte]] counts can now be performed by many analysers, giving an alternative to time-consuming manual counts. Many automated reticulocyte counts, like their manual counterparts, employ the use of a [[Supravital stain|supravital dye]] such as [[new methylene blue]] to stain the red cells containing [[Reticular fiber|reticulin]] prior to counting.<ref>{{cite web|url=http://www.biology-online.org/dictionary/New_methylene_blue|title=New methylene blue - Biology-Online Dictionary|website=www.biology-online.org|date=7 October 2019}}</ref> Some analysers have a modular slide maker which is able to both produce a blood film of consistent quality and stain the film, which is then reviewed by a medical laboratory professional.

===Coagulometers===
{{further|Coagulation testing}}
Automated coagulation machines or Coagulometers measure the ability of blood to clot by performing any of several types of tests including [[Partial thromboplastin time]]s, [[Prothrombin time]]s (and the calculated [[International normalized ratio|INRs]] commonly used for therapeutic evaluation), [[Lupus anticoagulant]] screens, [[D dimer]] assays, and factor assays.
 
Coagulometers require blood samples that have been drawn in tubes containing [[Trisodium citrate|sodium citrate]] as an anticoagulant. These are used because the mechanism behind the anticoagulant effect of sodium citrate is reversible. Depending on the test, different substances can be added to the blood plasma to trigger a clotting reaction. The progress of clotting may be monitored optically by measuring the absorbance of a particular wavelength of light by the sample and how it changes over time.
[[File:StaRRsed Inversa, automated Westergren based ESR 'analyzer'.jpg|thumb|upright=0.55|right|StaRRsed Inversa, automated Westergren-based ESR 'analyzer']]..

===Other hematology apparatus===
Automatic [[erythrocyte sedimentation rate]] (ESR) readers, while not strictly analysers, do preferably have to comply to the 2011-published CLSI (Clinical and Laboratory Standards Institute) "Procedures for the Erythrocyte Sedimentation Rate Test: H02-A5 and to the ICSH (International Council for Standardization in Haematology) published "ICSH review of the measurement of the erythrocyte sedimentation rate", both indicating the only  reference method, being Westergren, explicitly indicating the use of '''diluted''' blood (with sodium citrate), in 200&nbsp;mm pipettes, bore 2.55&nbsp;mm. After 30 or 60 minutes being in a vertical position, with no draughts and vibration or direct sunlight allowed, an optical reader determines how far the [[Red blood cell|red cells]] have fallen by detecting the level.