title: Determination of specimen storage conditions for measuring isoagglutinin titers.
abstract: BACKGROUND
  This study aimed to determine the optimal specimen storage conditions for isoagglutinin titration by changing storage time and temperature.
  
  
  METHODS
  Serum specimens from 60 individuals were stored at room temperature (RT, 25 °C) or at 4 °C and tested every 24 hours until 96 hours by the immediate spin (IS) method and the anti-human globulin method using dithiothreitol (DTT-AHG). These titer results were compared with the titers which were measured when the samples arrived. The titer endpoint was defined as the highest dilution, with clinically meaningful differences defined as more than 4-fold differences (two serial dilutions) in titer.
  
  
  RESULTS
  Of the specimens stored at RT for 24, 48, 72, and 96 hours, 5%, 12%, 12%, and 12%, respectively, showed two-fold (one dilution) differences by the IS method, and 8%, 8%, 8%, and 10%, respectively, showed two-fold (one dilution) differences with the DTT-AHG method. Of the specimens refrigerated for 24, 48, 72, and 96 hours, 8%, 10%, 13%, and 13%, respectively, showed two-fold (one dilution differences) by the IS method, and 13%, 12%, 12%, and 12%, respectively, showed two-fold (one dilution) differences with the DTT-AHG method.
  
  
  CONCLUSIONS
  Specimens stored for up to 96 hours at RT and 4 °C showed similar titers using the IS and DTT-AHG methods. These findings suggest that tests can be scheduled regularly.
authors: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea.
authors: Hee Seoung
authors: HS
authors: Seo
authors: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea.
authors: Ji Yeon
authors: JY
authors: Sohn
authors: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea.
authors: Joo-Hyoung
authors: JH
authors: Hwang
authors: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea.
authors: Yoon Kyung
authors: YK
authors: Song
authors: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea.
authors: Tea-Kyu
authors: TK
authors: An
authors: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea; Department of System Cancer Science, The Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Republic of Korea. Electronic address: ksy@ncc.re.kr.
authors: Sun-Young
authors: SY
authors: Kong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001782:Blood Donors; D001793:Blood Preservation; D005260:Female; D006388:Hemagglutinins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D006388:Hemagglutinins
keywords: Isoagglutinin; Refrigeration; Room temperature; Specimen; Storage; Titer