Injectable drugs manufactured in E. coli must be tested for host residual DNA (hr DNA) impurity in ensuring drug purity and safety. Because of low allowable hr DNA as impurity, highly sensitive methods are needed. Dro...Injectable drugs manufactured in E. coli must be tested for host residual DNA (hr DNA) impurity in ensuring drug purity and safety. Because of low allowable hr DNA as impurity, highly sensitive methods are needed. Droplet digital PCR (ddPCR) is a new method where the reaction is partitioned into about 20,000 nanoliter-sized droplets and each droplet acts as individual PCR reaction. After completion of end-point PCR, droplets are analyzed for fluorescence and categorized as positive or negative and DNA quantified using Poisson statistics. Here we describe development of a direct E. coli hr DNA dd PCR method where the drug is directly added to the ddPCR reaction. We show that the ddPCR method has acceptable precision and high accuracy, works with different biologic drugs, and compared to qPCR shows higher tolerance of drug matrices. The method does not require DNA extraction or standard curves for quantification of hr DNA in unknown samples.展开更多
【目的】建立一种基于单碱基突变的双向等位基因特异PCR(bi-directional PCR amplification of specific alleles,Bi-PASA)技术,并将其应用于杏单核苷酸多态性分型研究。【方法】利用直接测序的方法在2份不同果肉质地杏EXP基因的DNA序...【目的】建立一种基于单碱基突变的双向等位基因特异PCR(bi-directional PCR amplification of specific alleles,Bi-PASA)技术,并将其应用于杏单核苷酸多态性分型研究。【方法】利用直接测序的方法在2份不同果肉质地杏EXP基因的DNA序列上发现1个单碱基变异。在其上、下游两端设计双向等位基因特异性引物及其外侧互补引物,对120份杏材料的SNP进行分型。同时,对部分材料的基因型进行测序验证。【结果】利用双向等位基因特异PCR对杏EXP基因315 bp处SNP分型结果与直接测序完全一致。【结论】双向等位基因特异PCR技术是一种简单、经济、快速而可靠的SNP分型方法,可有效地应用于杏基因组上已知SNP突变的分型研究。展开更多
文摘Injectable drugs manufactured in E. coli must be tested for host residual DNA (hr DNA) impurity in ensuring drug purity and safety. Because of low allowable hr DNA as impurity, highly sensitive methods are needed. Droplet digital PCR (ddPCR) is a new method where the reaction is partitioned into about 20,000 nanoliter-sized droplets and each droplet acts as individual PCR reaction. After completion of end-point PCR, droplets are analyzed for fluorescence and categorized as positive or negative and DNA quantified using Poisson statistics. Here we describe development of a direct E. coli hr DNA dd PCR method where the drug is directly added to the ddPCR reaction. We show that the ddPCR method has acceptable precision and high accuracy, works with different biologic drugs, and compared to qPCR shows higher tolerance of drug matrices. The method does not require DNA extraction or standard curves for quantification of hr DNA in unknown samples.
文摘【目的】建立一种基于单碱基突变的双向等位基因特异PCR(bi-directional PCR amplification of specific alleles,Bi-PASA)技术,并将其应用于杏单核苷酸多态性分型研究。【方法】利用直接测序的方法在2份不同果肉质地杏EXP基因的DNA序列上发现1个单碱基变异。在其上、下游两端设计双向等位基因特异性引物及其外侧互补引物,对120份杏材料的SNP进行分型。同时,对部分材料的基因型进行测序验证。【结果】利用双向等位基因特异PCR对杏EXP基因315 bp处SNP分型结果与直接测序完全一致。【结论】双向等位基因特异PCR技术是一种简单、经济、快速而可靠的SNP分型方法,可有效地应用于杏基因组上已知SNP突变的分型研究。
