Editing Automated analyser (section)

===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.