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Title: Bacteria-killing ability of fresh blood plasma compared to frozen blood plasma

In recent years, the bacteria-killing assay (BKA) has become a popular technique among ecoimmunologists. New variations of that assay allow researchers to use smaller volumes of blood, an important consideration for those working on small-bodied animals. However, this version of the assay requires access to a lab with a nanodrop spectrophotometer, something that may not be available in the field. One possible solution is to freeze plasma for transport; however, this assumes that frozen plasma samples will give comparable results to fresh ones. Here, we tested this assumption using plasma samples from three species of birds: chickens (Gallus gallus), ash-throated flycatchers (Myiarchus cinerascens), and western bluebirds (Sialia mexicana). Chicken plasma samples lost most or all of their bacterial killing ability after freezing. This did not happen in flycatchers and bluebirds; however, frozen plasma did not produce results comparable to those obtained using fresh plasma. Finally, we caution researchers using the BKA to use fresh samples whenever possible, and to validate the use of frozen samples on a species-by-species basis.
 [1] ; ORCiD logo [2]
  1. Univ. of California, Riverside, CA (United States). Dept. of Biology
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1095-6433; TRN: US1800891
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology
Additional Journal Information:
Journal Volume: 191; Journal Issue: C; Journal ID: ISSN 1095-6433
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
Country of Publication:
United States
60 APPLIED LIFE SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; Ecological immunology; Microbicidal ability of blood; Repeatability
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1400017