Fig. 1. Chemical fingerprint discrimination of leaf tissues of transgenic and non-transgenic maize isolines of Benicia (Bt, •; non-Bt, ) and Nobilis (Bt, ; non-Bt, ) (A). No discrimination of isolines of Prelude (Bt, ; non-Bt, ) and DKC 3420 (Bt, ; non-Bt, ) (B). Discriminant function analysis was performed on volatile organic compound data from the head space of leaf tissues collected in the field at maize maturity stage in 2002 and 2003.