The preparation of polyclonal antibody against chlordimeform and establishment of detection by indirect competitive ELISA

Objective: Chlordimeform is a chemical pesticide that is highly carcinogenic and toxic. The purpose of this study was to establish an enzyme-linked immunosorbent assay (ELISA) method for the detection of chlordimeform in aquaculture and fish farming.

METHODS

Chlordimeform was coupled with bovine serum albumin (BSA) and ovalbumin (OVA) as carrier proteins. A chlordimeform-BSA conjugate was used as an immunogen, and chlordimeform-OVA was used as a coating antigen. Chlordimeform-BSA was used to immunize rabbits, and a polyclonal antibody was prepared. An indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was established to detect chlordimeform.

RESULTS

The working range of the established IC-ELISA method for chlordimeform detection was 1-20 ng/mL. The IC₅₀ was 3.126 ng/mL, and the lower limit of detection (LOD) of chlordimeform was 0.637 ng/mL. The recovery of chlordimeform from spiked water samples ranged from 81% to 107%.

CONCLUSION

An anti-chlordimeform polyclonal antibody was successfully developed, and a novel IC-ELISA was established to detect chlordimeform in aquaculture.

Development of an enzyme-linked immunosorbent assay for detection of clopidol residues in chicken tissues

BACKGROUND

Clopidol is mainly used for the prevention and treatment of coccidiosis, which poses a serious potential hazard to public health, in veterinary medicine. The aim of this study was to prepare monoclonal antibodies (mAbs) against clopidol (CLOP) and develop an immunoassay for detecting CLOP residues in chicken tissues. After derivation, CLOP hapten was conjugated to carrier proteins to synthesize the artificial antigen, and immunized Balb/C mice were employed to screen mAbs.

RESULTS

A sensitive hybridoma named C1G3 was screened out and two indirect competitive enzyme-linked immunosorbent assay (icELISA) standard curves were established. For the traditional two-step assay the linear range was from 0.06 to 98 ng mL(-1) , with half-maximal inhibitory concentration (IC50 ) and limit of detection (LOD) values of 2.76 ng mL(-1) and 0.03 ng mL(-1) respectively, while the rapid one-step icELISA had a working range from 0.08 to 102 ng mL(-1) , with IC50 and LOD values of 3.52 ng mL(-1) and 0.03 ng mL(-1) respectively. It was also indicated that a 10-fold dilution in chicken muscles gave an inhibition curve almost the same as that obtained in phosphate-buffered saline. When applied to spiking tests in chicken samples, the correlation coefficient (R(2) ) between concentrations added and measured was 0.9534.

CONCLUSION

The results of this study suggest that the immunoassay described is a promising alternative for screening CLOP residues in biological matrices and is suitable for routine diagnostics.