Similarly, Lipp et al. (2001) showed that DNA degradation might result in a significant decrease in the amount of DNA fragments that are sufficiently long to allow for the detection of GMOs in foods. In our study, 5 of the lectin-negative soy-containing products used soy lecithin as the soy source; the difficulty of extracting a sufficient amount of DNA from lecithin has been reported by other researchers as well (Lockley & Bardsley, 2000).