Bt-Cry1Ab/1Ac ELISA assay is used as an analytical tool for quantitative laboratory screening of presence or absence of Bt-Cry1Ab/1Ac proteins in leaves, seedlings and seeds of transgenic crop varieties like cotton. The assay can be used to detect the presence of these proteins in cotton products including Bollgard? and Widestrike?. (For use in assessment of transgenic proteins in Agriculture Only. Not for use in Human or Animal diagnostic or therapeutic procedures.)