AWWA JAW49887

Flow cytometer-derived fluorescence measurements were used to evaluate lot-to-lot variability, cross-reactivity, and avidity of four antibodies. Variability within kit 3 and 4 antibody lots was great, whereas kits 1 and 2 stained parasites consistently. Kit 3 and 4 anitbodies cross-reacted with non-parvum Cryptosporidium, kit l and 4 antibodies cross-reacted with Giardia muris. Kit l (primary only), 2, and 3 anti-cryptosporidium antibodies formed low-avidity complexes, unlike those in kits l (secondary) and 4 and all Giardia antibodies. Additionally, the authors quantified the ability of antibodies to bind stressed and unstressed parasites following methodological processing. The studies identified significant differences in antibody characteristics and performance. Includes 27 references, tables, figures.