Detection and removal of Escherichia coli using fluorescein isothiocyanate conjugated monoclonal antibody immobilized on bacterial magnetic particles.
A novel fluoroimmunoassay method using bacterial magnetic particles for the highly sensitive detection of bacteria has been developed. Fluorescein isothiocyanate (FITC) conjugated monoclonal anti-Escherichia coli antibody was immobilized onto bacterial magnetic particles (BMPs) using a heterobifunctional reagent, N-succinimdyl 3-(2-pyridyldithio)propionate (SPDP). E. coli cells were reacted with FITC-antibody-BMP conjugates for 15 min in an inhomogeneous magnetic field which enhanced aggregation. The cell/BMP complexes sedimented, causing relative fluorescence intensity of the solution to decrease with increasing microbial cell concentration. A linear relationship was obtained between the relative fluorescence intensity and cell concentration in the range of 10(2)-10(6) cells/mL. Selectivity of this detection system was satisfactory. Monoclonal antibody immobilized on BMPs was also applied to the specific removal of E. coli from the bacterial suspension.
Nakamura
N
N
Department of Biotechnology, Tokyo University of Agriculture and Technology, Japan.
Burgess
J G
JG
Yagiuda
K
K
Kudo
S
S
Sakaguchi
T
T
Matsunaga
T
T
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry* / Q000302:isolation & purification; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D015200:Fluoroimmunoassay; D008280:Magnetics
D000911:Antibodies, Monoclonal; D016650:Fluorescein-5-isothiocyanate