title: Impact of technical and assay variation on reporting of hemolysis in stored red blood cell products.
abstract: BACKGROUND
  Hemolysis of RBCs is an important measure of product quality and is influenced by donor factors, blood component manufacturing and storage. Percent hemolysis is determined using hematocrit (Hct), supernatant Hb (SHb) and total Hb (THb), each of which can be measured using a variety of methods.
  
  
  METHODS
  Sixteen members of an international collaborative were surveyed to understand equipment and procedural variation in hemolysis testing. In a laboratory-based evaluation, we examined how hemolysis was impacted by: measurement of Hct, SHb, THb and number and force of centrifugations for SHb preparation. The number and size of extracellular vesicles (EVs) was also examined.
  
  
  RESULTS
  There was no consensus in equipment or procedures used by international laboratories to measure hemolysis. The centrifugation force used to prepare samples influenced SHb concentration when a single or double (p=0.0001) centrifugation step was used. The number and force of centrifugation related directly to the ability to remove EVs and EV-bound Hb from samples. Hemolysis varied significantly from 0.16% to 0.32% (mean of 0.22%) depending on the combination of methods or centrifugation conditions used to test expired samples.
  
  
  CONCLUSIONS
  Method and preparative procedures have a critical impact on measurement of hemolysis in RCC.
authors.affiliation: Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Ruqayyah J
authors.initials: RJ
authors.lastname: Almizraq
authors.affiliation: Centre for Innovation, Canadian Blood Services, Edmonton, AB, Canada.
authors.forename: Qi Long
authors.initials: QL
authors.lastname: Yi
authors.affiliation: Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada; Centre for Innovation, Canadian Blood Services, Edmonton, AB, Canada. Electronic address: jason.acker@blood.ca.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Acker
authors.affiliation: Biomedical Excellence for Safer Transfusion (BEST) Collaborative, Lebanon, NH, United States.
mesh_terms: D001782:Blood Donors; D001800:Blood Specimen Collection; D004912:Erythrocytes / Q000737:chemistry / Q000166:cytology*; D000067128:Extracellular Vesicles / Q000378:metabolism; D006400:Hematocrit; D006403:Hematologic Tests / Q000379:methods*; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D006801:Humans; D012107:Research Design
chemical_list: D006454:Hemoglobins
keywords: Blood bank; Drabkin's method; Erythrocytes; Harboe; HemoCue; Hemoglobin; Quality control