RESUMEN
Interaction modes of carbaryl and DNA were studied by resonance light scattering (RLS) spectra and absorption spectra. Experiments show that at pH 1.97, there are two interaction modes between carbaryl and ctDNA, namely surface assembly mode and intercalative mode. Interaction mode has a relation with the concentration ratio of carbaryl to ctDNA. Under this condition, the RLS intensity o f carbaryl and ctDNA is proportional to the concentration of ctDNA. According to this, one new simple and rapid method of determining ctDNA was set up. The linear ranges of the concentration of ctDNA were 0.02-3 microg x mL(-1), the linear regression equation was I = 200.77c (microg x mL(-1)) + 118.91, and the correlation coefficient was r = 0.998 9. This method has successfully been used to determine the synthetic samples.