An ELISA-like time-resolved fluorescence immunoassay for microcystin detection.
BACKGROUND
A time-resolved fluorescence immunoassay (TRFIA), based on anti-microcystin-LR (MCLR) monoclonal antibodies (MAbs) and europium-labeled antimouse IgG conjugate, was first developed for microcystin detection.


METHODS
Anti-MCLR MAbs were prepared by a standard method, and the attained MAbs showed a good cross reactivity with MCLR, MCRR and MCYR. The TRFIA was performed in an indirect competitive mode. The detection method of TRFIA was compared with indirect competitive enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC).


RESULTS
The TRFIA exhibited a typical sigmoidal response for MCLR at concentrations of 0.005-50 ng/ml, with a wide quantitative range between 0.01 and 10 ng/ml, indicating the broadest detective range and the most sensitive of all the methods for microcystins (MCs) detection. Additionally, the TRFIA maintained good reliability through its quantitative range, as evidenced by low coefficients of variation (1.6-12.2%). The toxin data of algal samples assayed from TRFIA were in the same range as those with ELISA and HPLC, implying that the method was reliable and practical for the detection of MCs.


CONCLUSIONS
The TRFIA may offer a valuable alternative or a substitute for conventional ELISA for microcystin detection.
Lei
La-Mei
LM
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, CAS, Donghu Nanlu No. 7, Wuchang, Wuhan 430072, PR China.
Wu
Ying-Song
YS
Gan
Nan-Qin
NQ
Song
Li-Rong
LR
D000818:Animals; D000911:Antibodies, Monoclonal; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D015200:Fluoroimmunoassay / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D052998:Microcystins; D010456:Peptides, Cyclic / Q000032:analysis* / Q000276:immunology; D015203:Reproducibility of Results
D000911:Antibodies, Monoclonal; D052998:Microcystins; D010456:Peptides, Cyclic; C078588:microcystin