Editing Flow cytometry (section)

=== Fluidics system of a flow cytometer ===
Cells must pass uniformly through the center of focused laser beams to accurately measure optical properties of cells in any flow cytometer.<ref name=":1">{{cite journal | vauthors = Cossarizza A, Chang HD, Radbruch A, Akdis M, Andrä I, Annunziato F, Bacher P, Barnaba V, Battistini L, Bauer WM, Baumgart S, Becher B, Beisker W, Berek C, Blanco A, Borsellino G, Boulais PE, Brinkman RR, Büscher M, Busch DH, Bushnell TP, Cao X, Cavani A, Chattopadhyay PK, Cheng Q, Chow S, Clerici M, Cooke A, Cosma A, Cosmi L, Cumano A, Dang VD, Davies D, De Biasi S, Del Zotto G, Della Bella S, Dellabona P, Deniz G, Dessing M, Diefenbach A, Di Santo J, Dieli F, Dolf A, Donnenberg VS, Dörner T, Ehrhardt GR, Endl E, Engel P, Engelhardt B, Esser C, Everts B, Dreher A, Falk CS, Fehniger TA, Filby A, Fillatreau S, Follo M, Förster I, Foster J, Foulds GA, Frenette PS, Galbraith D, Garbi N, García-Godoy MD, Geginat J, Ghoreschi K, Gibellini L, Goettlinger C, Goodyear CS, Gori A, Grogan J, Gross M, Grützkau A, Grummitt D, Hahn J, Hammer Q, Hauser AE, Haviland DL, Hedley D, Herrera G, Herrmann M, Hiepe F, Holland T, Hombrink P, Houston JP, Hoyer BF, Huang B, Hunter CA, Iannone A, Jäck HM, Jávega B, Jonjic S, Juelke K, Jung S, Kaiser T, Kalina T, Keller B, Khan S, Kienhöfer D, Kroneis T, Kunkel D, Kurts C, Kvistborg P, Lannigan J, Lantz O, Larbi A, LeibundGut-Landmann S, Leipold MD, Levings MK, Litwin V, Liu Y, Lohoff M, Lombardi G, Lopez L, Lovett-Racke A, Lubberts E, Ludewig B, Lugli E, Maecker HT, Martrus G, Matarese G, Maueröder C, McGrath M, McInnes I, Mei HE, Melchers F, Melzer S, Mielenz D, Mills K, Mirrer D, Mjösberg J, Moore J, Moran B, Moretta A, Moretta L, Mosmann TR, Müller S, Müller W, Münz C, Multhoff G, Munoz LE, Murphy KM, Nakayama T, Nasi M, Neudörfl C, Nolan J, Nourshargh S, O'Connor JE, Ouyang W, Oxenius A, Palankar R, Panse I, Peterson P, Peth C, Petriz J, Philips D, Pickl W, Piconese S, Pinti M, Pockley AG, Podolska MJ, Pucillo C, Quataert SA, Radstake TR, Rajwa B, Rebhahn JA, Recktenwald D, Remmerswaal EB, Rezvani K, Rico LG, Robinson JP, Romagnani C, Rubartelli A, Ruckert B, Ruland J, Sakaguchi S, Sala-de-Oyanguren F, Samstag Y, Sanderson S, Sawitzki B, Scheffold A, Schiemann M, Schildberg F, Schimisky E, Schmid SA, Schmitt S, Schober K, Schüler T, Schulz AR, Schumacher T, Scotta C, Shankey TV, Shemer A, Simon AK, Spidlen J, Stall AM, Stark R, Stehle C, Stein M, Steinmetz T, Stockinger H, Takahama Y, Tarnok A, Tian Z, Toldi G, Tornack J, Traggiai E, Trotter J, Ulrich H, van der Braber M, van Lier RA, Veldhoen M, Vento-Asturias S, Vieira P, Voehringer D, Volk HD, von Volkmann K, Waisman A, Walker R, Ward MD, Warnatz K, Warth S, Watson JV, Watzl C, Wegener L, Wiedemann A, Wienands J, Willimsky G, Wing J, Wurst P, Yu L, Yue A, Zhang Q, Zhao Y, Ziegler S, Zimmermann J | display-authors = 6 | title = Guidelines for the use of flow cytometry and cell sorting in immunological studies | journal = European Journal of Immunology | volume = 47 | issue = 10 | pages = 1584–1797 | date = October 2017 | pmid = 29023707 | doi = 10.1002/eji.201646632 | pmc = 9165548 | s2cid = 25591889 | doi-access = free }}</ref><ref name=":2">{{Cite news|url=https://www.bio-rad-antibodies.com/flow-cytometry-fluidics-system.html|title=Fluidics System - Flow Cytometry Guide|work=Bio-Rad|access-date=2018-09-18|language=en}}</ref><ref name=":3">{{Cite web|url=https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-analysis-learning-center/molecular-probes-school-of-fluorescence/flow-cytometry-basics/flow-cytometry-fundamentals/how-flow-cytometer-works.html|title=How a Flow Cytometer Works|website=Thermo Fisher Scientific|language=en-US|access-date=2018-09-18}}</ref> The purpose of the fluidic system is to move the cells one by one through the lasers beam and throughout the instrument. Fluidics in a flow cytometer with cell sorting capabilities also use the stream to carry sorted cells into collection tubes or wells.<ref name=":1" />

==== Hydrodynamic focusing ====
{{main|Hydrodynamic focusing}}
For precise positioning of cells in a liquid jet, hydrodynamic focusing is used in most cytometers.<ref name=":1" /><ref name=":2" /> The cells in suspension enter into the instrument enclosed by an outer sheath fluid. The sample core is maintained in the center of the sheath fluid. The sample input rate or how fast the cells flow through to the laser interrogation can be controlled by the pressure of the sheath fluid on the sample core. Under optimal conditions, the central fluid stream and sheath fluid do not mix.{{cn|date=April 2022}}

==== Acoustic-assisted hydrodynamic focusing ====
Acoustic focusing technology is used in some flow cytometers to support hydrodynamic focusing.<ref name=":1" /><ref name=":3" /> Acoustic waves (>2&nbsp;MHz) pre-focus the sample before introduction to sheath fluid. The pre-focused sample is then injected into the hydrodynamic core and flowed through the instrument. This may help with increasing data accuracy under high sample input rates.