抄録
Biotin determination in blood has been usually carried out with either microbiological methods or competitive protein binding methods (binding assay). Blood samples are either hydrolyzed with H_2SO_4 by autoclaving or treated by papain to release free biotin from protein bound biotin. Thus, we tried to determine serum biotin levels of Japanese women using these procedures. The biotin levels of women's serum treated with papain were 2.3±0.51 ng/ml (n=31) as measured by a microbiological assay and 3.6 ± 0.72 ng/ml (n=31) by a binding assay. We found that for the papain treatment much longer incubation time (4 days) was needed than the overnight as previously reported. We proposed a new binding assay by using polystyrene beads and biotinylated houseradish peroxidase. This assay is a sensitive (0.02-0.4 ng/assay tube) and simple method which does not need any special equipments.
