Ma Huimin, Zhang Wenbing, Hu Junjie, Yu Zhiqiang, Chen Yong, Luo Qiong, Shi Xiaoliu, Zhang Yingying, Song Renfang, Zhou Zhen, Shen Guoying, Fu Jiamo
State Key Laboratory of Organic Geochemistry, Guangzhou Research Center of Mass Spectrometry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.
Eur J Mass Spectrom (Chichester). 2009;15(4):555-61. doi: 10.1255/ejms.1007.
DNA methylation plays an important role in both normal physiological and disease processes. In this study, a sensitive and precise liquid chromatography-electrospray ionization tandem mass spectrometry method has been optimized for quantification of global DNA -methylation levels in human peripheral blood by using multiple reaction monitoring (MRM) mode. This method was then used to analyze age-dependent association of DNA methylation. The results showed that the limit of detection was 1 pg for 5-methyl-2'-dexycytidine (5mdC) (S/N = 5.6). The linear calibration curves with correlation coefficients higher than 0.9990 were ranged 0.75-10 ppm and 0.0375-0.5 ppm for 2'-dexycytidine (dC) and 5mdC, respectively. The relative standard derivatives (RSD) of inter-day, intra-day and parallel samples were less than 5%. The analysis results of the blood samples from 60 healthy individuals showed that the child group had the highest mean 5mdC content while the adult group had the lowest values.
DNA甲基化在正常生理过程和疾病过程中均发挥着重要作用。在本研究中，已优化了一种灵敏且精确的液相色谱 - 电喷雾电离串联质谱法，通过多反应监测（MRM）模式来定量测定人外周血中的整体DNA甲基化水平。然后使用该方法分析DNA甲基化与年龄的相关性。结果表明，5 - 甲基 - 2'-脱氧胞苷（5mdC）的检测限为1 pg（S/N = 5.6）。2'-脱氧胞苷（dC）和5mdC的线性校准曲线相关系数均高于0.9990，范围分别为0.75 - 10 ppm和0.0375 - 0.5 ppm。日间、日内和平行样品的相对标准偏差（RSD）均小于5%。对60名健康个体的血液样本分析结果显示，儿童组的平均5mdC含量最高，而成人组的含量最低。
