title: Platelet counting using plasma platelet concentrate samples.
abstract: Platelet counting using samples of plasma from platelet concentrates prepared for transfusion was assessed. The methods employed included a manual phase-contrast method, and counting with Coulter S Plus and Sysmex E-2500 counters. All methods were reproducible (mean CV of 4.9, 2.2 and 1.4%, respectively). However, neat samples of platelet concentrates analysed by Coulter counter were inaccurate (mean count of 863.8 x 10(9)/l compared to 1018.9 x 10(9)/l counted manually). Moreover, the Coulter platelet counts were non-linear above 900 x 10(9)/l, whereas the E-2500 platelet counts were linear to 2700 x 10(9)/l. A one-in-three pre-dilution was required to obtain accurate, linear counts with the Coulter counter, whereas the E-2500 was accurate without pre-dilution (mean count of 1030.2 x 10(9)/l compared to 1018.9 x 10(9)/l counted manually). In conclusion, the method of platelet counting may affect true platelet yields.
authors.affiliation: Wessex Regional Transfusion Centre, Southampton, U.K.
authors.forename: R A
authors.initials: RA
authors.lastname: Lord
authors.forename: G A
authors.initials: GA
authors.lastname: Smith
authors.forename: M J
authors.initials: MJ
authors.lastname: Nightingale
authors.forename: F E
authors.initials: FE
authors.lastname: Boulton
mesh_terms: D001331:Automation; D006801:Humans; D016014:Linear Models; D010976:Platelet Count / Q000379:methods*; D015203:Reproducibility of Results