Development of an immunochromatographic test strip for the detection of procaine in milk

Procaine (PRC) is a local anaesthetic used in the treatment of several disease related to ageing, asthma, and arthritis. In this study, we describe a rapid, sensitive, simple, and accurate method for the determination of PRC in milk, using an immunochromatographic test strip. For the immunochromatographic test, antigen (PRC-bovine serum albumin) and goat anti-mouse IgG were drawn onto a nitrocellulose membrane representing the control line and test line. The test was developed with a sensitive monoclonal antibody specific for PRC, generated by immunizing BALB/c mice with a well-characterized PRC- Keyhole limpet hemocyanin conjugate, produced in our laboratory. Under optimized conditions, the semi-quantitative test strip was able to detect PRC at concentrations down to 1 ng/mL in both 0.01 M phosphate buffer saline (pH 7.4) and milk samples. All results were obtained within 5 min. Our data indicate that the immunochromatographic assay is capable of sensitive, rapid, and specific on-site screening of PRC.