La. Tempelman et al., QUANTITATING STAPHYLOCOCCAL-ENTEROTOXIN-B IN DIVERSE MEDIA USING A PORTABLE FIBEROPTIC BIOSENSOR, Analytical biochemistry, 233(1), 1996, pp. 50-57
A new, portable fiber-optic biosensor has been used to detect staphylo
coccal enterotoxin B, a causative agent of food poisoning, at levels a
s low as 0.5 ng/ml in buffer. The toxin (SEE) can also be detected and
quantitated in other relevant media: human serum, urine, and aqueous
extract of ham. The level of toxin, from 5 to 200 ng/ml, can be accura
tely predicted in these media by calibrating each fiber and by compari
ng results to a single standard curve based on toxin in buffer. The qu
antitative fluorescent sandwich immunoassay provides results in 45 min
; qualitative results are provided in 15-20 min, Using a blender and a
benchtop centrifuge, fast, simple aqueous extracts of contaminated ha
m samples were prepared and tested. Ham spiked with 5 or 40 mu g SEE p
er 100 g food resulted in biosensor readings indicative of 11 or 69% r
ecovery of the toxin, respectively, Finally, the SEE assay is highly s
pecific; SEA and SED give only 2-3% of the signal at 5000 ng/ml as SEE
gives at 1000 ng/ml. This specific, sensitive assay for SEE on the po
rtable fiberoptic biosensor permits easy monitoring of clinical sample
s or on-site analysis of suspect food samples. (C) 1996 Academic Press
, Inc.