Detection and Removal of Escherichia coli Using Fluorescein Isothiocyanate Conjugated Monoclonal Antibody Immobilized on Bacterial Magnetic Particles

Noriyuki Nakamura, J. Grant Burgess, Kaoru Yagiuda, Satoko Kudo, Toshifumi Sakaguchi, Tadashi Matsunaga

Research output: Contribution to journalArticle

81 Citations (Scopus)


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 102-106 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.

Original languageEnglish
Pages (from-to)2036-2039
Number of pages4
JournalAnalytical Chemistry
Issue number15
Publication statusPublished - 1993 Aug 1
Externally publishedYes


ASJC Scopus subject areas

  • Analytical Chemistry

Cite this