title: Impact of sample volume and handling time during analysis on the in vitro quality measurements of platelet concentrates held in syringes.
abstract: BACKGROUND
  The determination of quality parameters is a necessity for monitoring the efficacy of platelet concentrates. During consolidated quality control studies, there may be a large number of samples to be analyzed at the same time. This common workflow setup triggered the question whether there is an influence of the number of samples to be analyzed on the accuracy of the test results.
  
  
  METHODS
  Two different sample volumes of platelet concentrates, 1 ml and 50 ml, were analyzed for a set of standard in vitro parameters including pCO(2), pO(2), pH, glucose, and lactate as well as platelet activation via CD62P expression and responsiveness to adinosine diphosphate in an extent-of-shape-change assay. To assess apoptotic mechanisms triggered by the hold time, changes in the phosphatidylserine exposure were monitored.
  
  
  RESULTS
  In total, eleven time points were assessed over a 3-h period as well as an overnight point for assay evaluation. Except for pCO(2) and pO(2), all in vitro parameters analyzed were unaffected by a sample hold time of up to 3-h.
  
  
  CONCLUSIONS
  Sampling for pO(2) determination should be carried out in small volumes and assessed within 30 min of collection to obtain reliable and comparable results.
authors.affiliation: Canadian Blood Services, University of British Columbia, Vancouver, BC, Canada. peter.schubert@blood.ca
authors.forename: P
authors.initials: P
authors.lastname: Schubert
authors.forename: B
authors.initials: B
authors.lastname: Culibrk
authors.forename: D
authors.initials: D
authors.lastname: Coupland
authors.forename: E
authors.initials: E
authors.lastname: Levin
authors.forename: D V
authors.initials: DV
authors.lastname: Devine
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001784:Blood Gas Analysis; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D001793:Blood Preservation / Q000295:instrumentation / Q000379:methods*; D002245:Carbon Dioxide / Q000378:metabolism; D005434:Flow Cytometry; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism*; D010313:Partial Pressure; D010718:Phosphatidylserines / Q000494:pharmacology; D015539:Platelet Activation / Q000187:drug effects; D010976:Platelet Count; D011786:Quality Control; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods*; D013594:Syringes; D013997:Time Factors
chemical_list: D019007:P-Selectin; D010718:Phosphatidylserines; D002245:Carbon Dioxide; D019344:Lactic Acid; D000244:Adenosine Diphosphate; D005947:Glucose; D010100:Oxygen