【摘要】 目的　探讨PCR反应体系中Mg2 + 浓度对从石蜡包埋组织中提取DNA进行PCR反应的影响。方法　从石蜡包埋组织中提取DNA ,PCR反应扩增甲状腺髓样癌RET基因第 13外显子 ,分析PCR反应体系中Mg2 + 浓度分别为1 5mmol L、2 0mmol L、2 5mmol L、3 0mmol L、4 0mmol L时PCR反应产物中目的基因含量及对PCR产物基因序列测定的影响。结果　 5种条件扩增的目的基因经纯化后DNA含量分别为 4 8ng μl(1 5mmol L)、2 6 6ng μl(2 0mmol L)、4 0 2ng μl(2 5mmol L)、38 5ng μl(3 0mmol L)、4 4 5ng μl(4 0mmol L) ;Mg2 + 浓度为 4 0mmol L时PCR产物电泳图见到多条非特异性条带 ;Mg2 + 浓度为 2 5mmol L时PCR产物直接测序反应曲线峰图背景噪音 (噪峰 )减小 ,信噪比 (信号 噪音 )增高。结论　从石蜡包埋组织中提取DNA行PCR反应 ,Mg2 + 浓度为 2 5mmol L时反应特异性强 ,PCR产物质量高。较高的Mg2 + 浓度可以增加PCR反应产量 ,但降低反应的特异性更多还原

【Abstract】 Objective To investigate Mg 2+ ionic concentration influence PCR that the DNA extraction from paraffin embedded tissues. Methods DNA was extracted from paraffin embedded tissues, exon 13 of RET gene was amplified by polymerase chain reaction in Chinese sporadic medullary thyroid carcinoma, the Mg 2+ ionic concentration of the PCR buffer are 1 5 mmol/L、2 0 mmol/L、2 5 mmol/L、3 0 mmol/L、4 0 mmol/L. Results The DNA quantity, after purify, of five different Mg 2+ ionic concentration conditions are 4 8 ng/μl(1 5 mmol/L)、26 6 ng/μl(2 0 mmol/L)、40 2 ng/μl(2 5 mmol/L)、38 5 ng/μl(3 0 mmol/L)、44 5 ng/μl(4 0 mmol/L). When the Mg 2+ ionic concentration is 4 0 mmol/L, we can see many no specific bands, and when the Mg 2+ ionic concentration is 2 5 mmol/L, we get the best sequencing map and more target DNA.Conclusion The best condition of Mg 2+ ionic concentration in PCR that the DNA extraction from paraffin embedded tissues is 2 5 mmol/L.更多还原