Development of a membrane-based immunofiltration assay for the detection of T-2 toxin.
An improved analytical device capable of performing simultaneous immunofiltration-based immunoassay on 30 samples in the presence of reference standards has been developed. The device consists of a rectangular membrane with 36 antibody spotted zones, one end of which was attached to a semirigid polyethylene card. A piece of wetted filter paper between the membrane and the polyethylene card absorbs the added reagent. The assay is a competitive one using T-2 toxin-horseradish peroxidase (T-2 toxin-HRP) as the labeled analyte and 4-chloro-1 naphthol (4CN) as the substrate. Signal amplification was done by the Super-CARD signal amplification method. Semiquantitative results were obtained by visual comparison of the color intensity of a sample spot with those of reference standards. Densitometric analysis was used for quantitation. The method allows rapid and easy determination of T-2 toxin in wheat and poultry feed with detection limits of 12.5 and 25 microg x kg(-)(1), respectively, with accuracy and precision. Matrix interference was eliminated by appropriate dilution of sample extracts with assay buffer. The detection sensitivity in ELISA was 10-fold higher than that in the membrane-based method. Noninfected samples were spiked with T-2 toxin at several concentrations and analyzed by the present method and rapid ELISA. Mean recoveries by both methods were between 80 and 108%. The correlation between the two methods was excellent (R(2) = 0.99).
Pal
Arindam
A
Department of Immunobiology, Indian Institute of Chemical Biology, 4, Raja S C Mullick Road, Jadavpur, Calcutta 700 032, India.
Acharya
Debopam
D
Saha
Debjani
D
Dhar
Tarun K
TK
D000821:Animal Feed; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D007118:Immunoassay / Q000379:methods*; D008566:Membranes / Q000378:metabolism; D013605:T-2 Toxin / Q000032:analysis* / Q000378:metabolism; D014908:Triticum / Q000737:chemistry
D013605:T-2 Toxin