Influences of cycle index and volume on sensitivity of DNA detection / 法医学杂志

ABSTRACT

OBJECTIVE@#To explore the feasibility of improving the sensitivity of DNA detection by increasing the PCR cycle index and decreasing the volume of amplifying system.@*METHODS@#The DNA of semen were collected from 10 healthy irrelevant volunteers, and were quantified to 50, 40, 30, 25, 20, 15, 10 pg/microL, separately. All samples were then amplified in 10, 5, 3 microL volume and at 28, 30, 32, 34, 36 cycles, respectively. 3130 genetic analyzer was used to detect 15 autosomal STR loci.@*RESULTS@#Under the situation of 28 cycles and 3 microL volume, samples which achieved > 40 pg/microL could be correctly typed. Under the situation of 10, 5, 3 microL volume, samples which achieved > 20 pg/microL could be correctly typed at 34 cycles. When increasing the index to 36 cycles, they could not be correctly typed because of the non-specific band.@*CONCLUSION@#DNA detecting sensitivity can be improved to a certain extent by increasing the cycle index and decreasing the volume of amplifying system.