RESUMO
Objective To develop a multiplex allele-specific PCR (AS-PCR) assay with three-color fluo-rescence labeling for mitochondrial DNA (mtDNA) SNP typing. Methods Based on the principle of AS-PCR, the primer sets were designed for 20 SNP located on the coding region of mtDNA and divided in-to 2 groups labeled with FAM and HEX fluorescence, respectively. A primer set included two forward (reverse) allelic specific primers with different sizes and a generic reverse (forward) primer. Blood sam-ples from 200 unrelated individuals were analyzed by AS-PCR and capillary electrophoresis. Three ran-dom samples at least for each SNP site were examined and verified by direct sequencing. The haplotype frequency was investigated. Results Distinct electropherograms of 200 blood samples were obtained suc-cessfully. The typing results of direct sequencing were identical to those obtained from AS-PCR. The minimum detectable DNA concentration was 0.2 pg under the system of 10μL. The sensitivity of the DNA concentrations ranged from 0.5 to 5 pg. The 200 individuals were assigned into 15 haplotype, and the haplotype diversity was 0.906 0. Conclusion AS-PCR is a simple, rapid and efficient method for mtDNA SNP typing, and can be applied to forensic practice.
RESUMO
Objective Training a few medical students as standardized patients to teach and test other medical students'physical examination skills is a good way to compensate the deficient teaching resources and improve the medical students'clinical capabilities.Methods We spent 12 class hours to train 6 students as standardized patients.Then we used these 6 students'standardized patients to help the teacher to educate medical students in experimental group,while students in the control group only had traditional class under the construction of the teachers as before.At last,we collected their final physical examination skills'score.Results The final physical examination skill score of experimental group(85.78?5.89)is higher than that of control group(84.53?4.64)(P