A method for the determination of nucleic acids with methylene blue(MB
) as a fluorescence probe was developed, based on the quenching of the
fluorescence of MB in the presence of nucleic acids. The calibration
graph was linear in the range of 0-40 mu g/ml for CT DNA and 0-55 mu g
/ml for yeast RNA, the limit of detection was 28 ng/ml for CT DNA and
82 ng/ml for yeast RNA. CT DNA could be determined in the presence of
30% (w/w) yeast RNA and yeast RNA was determined when the content of C
T DNA in synthetic samples was below 5% (w/w).