Abstract CELⅠ is a key enzyme in TILLING(Targeting Induced Local Lesions In Genomes)technology, and it can cleave heteroduplex DNAs with high specificity at sites of base mismatch and DNA distortion. Here we extracted CELⅠ from celery(Apium graveolens), and made detection by SDS-PAGE, which showed the main band at 43kD. Then used heteroduplex DNAs as the substracts, investigated the activity of CELⅠ. The results indicated that CELⅠ can cleave heteroduplex DNAs of different materials with high specificity at sites of base mismatch. Through the extraction of CELⅠ, activity investigation, and application for detection of gene polymorphism in rice, we will provide a simple and practicable method for detection of gene polymorphism.
