This invention provides a method for the extraction and detection of a peptide from transgenic plant tissues wherein a non-immunogenic solubility-promoting compound is used to release the enzyme into the solution fraction during the purification process. In some embodiments, this invention provides a method for the extraction and detection of the enzyme Amy797E, which is a heterologous thermo-tolerant α-amylase, from the tissues of corn event 3272 using a non-immunogenic amylase during the purification process. This invention allows for a limit of detection of 1:1000 of Amy797E in an enzyme-linked immunosorbent assay (ELISA).