Microcystin-LR (MC-LR) is one of the most common biotoxin that pollutes water and agricultural products. The study aims to obtain the high sensitive anti-MC-LR single-chain antibody (scFv) for detecting MC-LR. Here， a MC-LR-immunized rabbit phage display scFv library with its capacity of 3.26×10CFU/mL was constructed and used for anti-MC-LR phage scFv particles screening. After four rounds of biopanning， 18 positives were isolated and identified successfully. The most positive scFv (RscFv3) was expressed in Escherichia coli HB2151 and purified with a concentration of 796.7μg/mL， and the purified anti-MC-LR polyclonal antibodies (PAbs) were 3.6mg/mL. The PAbs and scFv based indirect competitive enzyme li... More
Microcystin-LR (MC-LR) is one of the most common biotoxin that pollutes water and agricultural products. The study aims to obtain the high sensitive anti-MC-LR single-chain antibody (scFv) for detecting MC-LR. Here， a MC-LR-immunized rabbit phage display scFv library with its capacity of 3.26×10CFU/mL was constructed and used for anti-MC-LR phage scFv particles screening. After four rounds of biopanning， 18 positives were isolated and identified successfully. The most positive scFv (RscFv3) was expressed in Escherichia coli HB2151 and purified with a concentration of 796.7μg/mL， and the purified anti-MC-LR polyclonal antibodies (PAbs) were 3.6mg/mL. The PAbs and scFv based indirect competitive enzyme linked immunosorbent assay (IC-ELISAs) were established for MC-LR and its analogues， and the results showed they all had high sensitive for MC-LR with detection limits of 0.03 and 0.05μg/L， and had strong cross-reactivity for MC-RR， MC-WR and MC-YR， respectively. The average recovery rate was 91.9% with coefficient of variation <6.8% for scFv-based IC-ELISA to detect MC-LR spiked in water samples， which met the requirement of indoor testing. The present results indicate that we have obtained a high sensitive anti-MC-LR scFv by the MC-LR-immunized phage library construction and screening， and the scFv-based IC-ELISA can be used for monitoring MC-LR in water samples.
