A Method Based on Nanobodies Against AMH to Establish Immunochromatography for Evaluation of Follicular Development in Bactrian Camels

(1) Background: Anti-Müllerian hormone (AMH) is a key indicator for predicting ovarian reserve and fertility. Currently, B-mode ultrasound examination is the primary method for evaluating follicular development in Bactrian camels, although it has several limitations. This study aims to develop a colloidal gold strip based on AMH nanobody preparation, establishing an efficient, simple, and rapid detection method suitable for evaluating follicular development. (2) Methods: Two nanobodies specifically binding to AMH were screened and identified from an alpaca naive nanobody library using phage display technology. The nanobodies were expressed in the yeast expression vector (pMCO-AOXα) and purified by affinity chromatography on a nickel column. Based on the purified nanobodies, a colloidal gold immunochromatographic strip was constructed for detecting serum AMH levels. (3) Results: In this study, anti-AMH nanobodies (AMH-VHH-A1 and AMH-VHH-A10) were expressed and purified; these were successfully utilized to prepare colloidal gold immunochromatographic strips for detecting AMH in serum. The T-line intensity of the colloidal gold detection was positively correlated with the number of growing follicles obtained by B-mode ultrasound imaging. (4) Conclusions: The colloidal gold strips based on nanobodies against AMH established in this research provided an effective, simple, rapid, and on-site method for evaluating follicular development, thus supplying a reference for reproductive management in Bactrian camels.