Development of a highly sensitive and specific monoclonal antibody-based enzyme-linked immunosorbent assay for determination of doxycycline in chicken muscle, liver and egg

Abstract

A modified indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) method was developed using a highly sensitive and specific monoclonal antibody (McAb) to determine doxycycline (DC) residues in chicken tissues and egg. The McAb against DC was produced by hybridoma technique and a modified ic-ELISA was characterised in terms of sensitivity, specificity, precision and accuracy. At optimal experimental conditions, the standard curve was constructed at concentrations ranged from 0.01 to 100 ng/ml. The IC(50) value was 1.32±0.18 ng/ml. The limit of detection was 0.14±0.02 ng/g. The recoveries of DC from spiked chicken liver, muscle, and egg at levels of 50-600 ng/g were 84.6-85.5%, 88.2-89.1%, and 84.4-89.3%, respectively. The coefficient variations (CVs) were 5.1-9.3%, 3.7-11.3%, and 4.7-9.8%, respectively. Linear regression analysis showed good correlation, with r(2) values 0.9909 for chicken liver and 0.9916 for chicken muscle.