Which antibody is used for detection of cry1Ac and cry2Ab insecticidal crystal protein in ELISA ?

what is the protocol for coating of antibody in the ELISA micro plate ?

Where to get these antibodies ?

I don't know about antibody sources, but coating a plate is pretty simple. You can use Hybond (or similar) plates that are pre-coated to have high protein absorption. Dilute the antibody appropriately in PBS (no BSA or other blocker at this stage) and coat onto plate and cover/seal. I have seen time frames recommended from 1 hour at room temperature to O/N at RT or 4C.

I have also used a 0.1mM solution of sodium bicarbonate to assist in the Ab binding to the plate, but apparently this is not always needed with high absorption plates.