Abstract: Objective To determine the optimal extraction process of bone DNA by comparing pretreatment and DNA extraction methods for bones from different parts. Methods Firstly, fresh bone samples were collected from a domestic cow, including one femur, one humerus and one rib. Secondly, bone powder was prepared by ball-milling and frozen grinding respectively. DNA was extracted by five methods including AutoMate Express^TM magnetic bead method. Finally, paired t-test and one-way ANOVA analysis were applied to compare the DNA concentration, purity and STR typing results under different extraction processes. Results In terms of yield, the ball-milling method had an advantage and the highest DNA concentration was extracted using the AutoMate ExpressTM magnetic bead method. In terms of purity, there was no significant difference between the two pretreatment methods. Using the AutoMate Express^TM magnetic bead method acquired the purest DNA. In terms of STR analysis results, the frozen grinding method combined with the AutoMate Express^TM magnetic bead method gave better STR typing results with a high rate of STR genotyping. In addition, rib is more likely to obtain the best DNA yield and STR results. Conclusion The combination of the AutoMate Express^TM magnetic bead method with frozen grinding method, a more ideal method of bone pretreatment, can greatly improve the efficiency of bone DNA recovery. Additionally, rib is more suitable for bone DNA identification in forensic practice.

Key words: bone, DNA extraction, pretreatment, STR typing, forensic genetics

摘要： 目的 比较不同部位骨骼预处理及脱氧核糖核酸（deoxyribonucleic acid，DNA）提取方法，以期确定骨骼DNA最优提取流程。方法 先收集一头家养牛的新鲜骨样本，包括股骨、肱骨和肋骨各一根，采用球磨法和冷冻研磨法制备骨粉，利用AutoMate Express^TM磁珠法等5种方法提取DNA，并运用配对t检验和单因素方差分析比较不同提取方法下DNA质量浓度、纯度和短串联重复序列（short tandem repeat，STR）分型结果。结果 在产量方面，球磨法具有较大优势，利用AutoMate Express^TM磁珠法提取的DNA质量浓度最高；在纯度方面，2种预处理方法无显著性差异，AutoMate Express^TM磁珠法提取的DNA纯度最高；在STR检测方面，冷冻研磨法结合AutoMate Express^TM磁珠法可获得较好的STR分型结果及基因座检出率。此外，肋骨更可能获得最佳DNA产量和STR检测结果。结论 冷冻研磨法是一种更为理想的骨骼预处理方法，在此基础上结合AutoMate ExpressTM磁珠法可极大提高骨骼DNA回收率。此外，肋骨更适用于骨骼DNA鉴定实践。

关键词: 骨骼, DNA提取, 预处理, STR分型, 法医遗传学