An ELISA method for quantitation of tubulin using poly-1-lysine coated microtiter plates

A new, sensitive and convenient ELISA method has been developed for quantitation of tubulin using poly-1-lysine (PLL) coated multiwell microtiter plates. Binding of tubulin to untreated plastic surface of microtiter plates was extremely poor. Coating of wells with PLL enhanced the binding and facilitated quantitation by ELISA. Binding of tubulin was followed by stepwise additions of rabbit anti-tubulin IgG, HRP-conjugated goat anti-rabbit IgG and colour reagent. The method has been successfully applied to quantitate the tubulin content of extracts from rat brain and liver as evident from the excellent correlation of the results with those obtained from 3H-colchicine binding assay. The detection limit is as low as 5 ng, which is relatively better than that of the previous RIA methods. The ELISA method does not involve the use of any radioactive compound and all reagents required for this assay are commercially available.