Development and production of monoclonal antibodies for the measurement of solanidine potato glycoalkaloids

Abstract

Although it is generally acknowledged solanidine glycoalkaloids found in domestic potato cultivars are of sufficient toxicity to require testing prior to the release of new varieties, the widespread use of one of the most promising analysis techniques, immunoassays, is hampered by the variability of polyclonal antibody that has been developed for these analyses. We report the development of a uniform monoclonal antibody (mouse IgG1) that binds to solanidine and demissidine alkaloids for use in immunoassays. The monoclonal producing hybridoma developed is sufficiently resilient to produce the antibody in protein free media, from which very pure antibody could be isolated by simple ammonium sulfate precipitation. The purified antibody can be freeze-dried for storage and performs well in immunoassays with very low background absorbances. The monoclonal antibody was used in the optimized immunoassay at a concentration of 200 ng/mL with only 10 ng/mL concentration required for detectable signals (titer). From half absorbance levels (I50 values) the antibody detected α-solanine the best (0.021 μM) while α-chaconine, demissidine and solanidine were detected at levels of 0.043, 0.092 and 0.103 μM, respectively.