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Yufa Peng

Publications and source records attributed to Yufa Peng.

4 recordsLinked to original sources

A novel real-time quantitative PCR method using attached universal template probe.

A novel real-time quantitative polymerase chain reaction (PCR) method using an attached universal template (UT) probe is described. The UT is an approximately 20 base attachment to the 5' end of a PCR primer, and it can hybridize with a complementary TaqMan probe. One of the advantages of this method is that different target DNA sequences can be detected employing the same UT probe, which substantially reduces the cost of real-time PCR set-up. In addition, this method could be used for simultaneous detection using a 6-carboxy-fluorescein-labeled UT probe for the target gene and a 5-hexachloro-fluorescein-labeled UT probe for the reference gene in a multiplex reaction. Moreover, the requirement of target DNA length for UT-PCR analysis is relatively flexible, and it could be as short as 56 bp in this report, suggesting the possibility of detecting target DNA from partially degraded samples. The UT-PCR system with degenerate primers could also be designed to screen homologous genes. Taken together, our results suggest that the UT-PCR technique is efficient, reliable, inexpensive and less labor-intensive for quantitative PCR analysis.

Bacillus thuringiensis Toxins↗

Geographic variation in susceptibility of Chilo suppressalis (Lepidoptera: Pyralidae) to Bacillus thuringiensis toxins in China.

Geographic variation in the susceptibility of the striped stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), in China to Bacillus thuringiensis (Bt) insecticidal crystal proteins Cry1Ac and Cry1Ab was studied to establish baseline information for comparing the future response of populations with increased exposure to Bt products. Rice is the major host of C. suppressalis, and Bt rice ma) be released in China in the near future. Twelve populations of the pest were collected from the major rice-growing regions of China. LC50 estimates were determined for all populations for Cry1Ac and for eight populations for Cry1Ab. The bioassay results indicated that the range of LC50 in neonate larvae to Cry1Ac and Cry1Ab was from approximately 15 to approximately 157 mg (AI)/L and approximately 2 to approximately 34 mg (AI)/L, respectively. LC50 values were lower for Cry1Ab than for Cry1Ac, and there was a significant positive correlation between the two toxins tested.

Animals↗