Establishment of a lateral flow colloidal gold immunoassay strip for the rapid detection of estradiol in milk samples

- A panel of monoclonal antibodies (mAb) specific for estradiol (E2) screening was produced.
- A lateral flow colloidal gold immunoassay strip for determining E2 in milk samples was established with the E2 mAb.
- The strip in this study could be used to detect the E2 residue within the range of 37.14-1484.65 pg/mL in prepared milk samples.

It is a fact that the level of estradiol (E2) in powdered milk has been increased manyfold with growing concerns on dairy safety. Our study produced a panel of monoclonal antibodies (mAb) specific for E2 screening and established a lateral flow colloidal gold immunoassay strip for determining E2 in milk samples with the E2 mAb. The sensitivity of the test strip was found to be 180.42 ± 3.17 pg/mL and the lower detection limit (LDL) value was 37.14 pg/mL. For negative milk samples spiked with 400, 800, and 1200 pg/mL, the recovery range was 86.7-93.5% and the coefficient of variation scope [CV (%)] was 4.8-6.2%. The results of comparative studies between test strips and HPLC were relatively identical while the strip test only required less than 8 min. In the study, the test strip was a practical screening technology for quantitative, semi-quantitative, or qualitative detection of E2 residues.