Jin M, Ba H J, Zhu A H, Ma J, Shi J W, Liu Y N, Lin Z Q
Institute of Forensic Science, Changzhou Public Security Bureau, Changzhou 213003, China.
Shanghai Key Laboratory of Crime Scene Evidence, Key Laboratory of Forensic Evidence and Science Technology, Ministry of Public Security, Institute of Forensic Science, Shanghai Public Security Bureau, Shanghai 200083, China.
Fa Yi Xue Za Zhi. 2018 Apr;34(2):157-160. doi: 10.3969/j.issn.1004-5619.2018.02.011. Epub 2018 Apr 25.
To explore the effect of benzidine test and related reagents on DNA analysis of bloodstain.
A total of 970 bloodstain filter paper samples with 1 μL venous blood were collected, and 10 of them acted as control samples. After benzidine test and related reagent processing, DNA of 960 samples was extracted by Chelex-100 and silica bead methods and then multiplex amplified by AmpFℓSTR™ Identifiler™ Plus PCR kits. The results of STR typing were compared between different groups.
DNA were extracted immediately after benzidine test. Totally STR loci （3.80±1.34） were detected by silica bead method, while no STR loci were obtained by Chelex-100 method. Thirteen samples （21.7%） with whole STR typing results were obtained by drying after benzidine test, and the STR locus number （12.90±1.49） which obtained by silica bead method was much higher than by Chelex-100 method （4.70±1.96） （<0.05）. When DNA was extracted immediately after the addition of glacial acetic acid, the STR locus number was （9.40±2.09） by silica bead method, but no STR typing result was obtained by Chelex-100 method. All 15 STR loci could be obtained by only adding glacial acetic acid after drying and only adding tetramethylbenzidine alcoholization liquid or 3% hydrogen peroxide liquid.
Benzidine test has significant influence on DNA analysis of bloodstain. The Chelex-100 method is not suitable for the DNA extraction of bloodstain after benzidine test. Drying after benzidine test and silica bead methods can effectively enhance the STR locus number of bloodstain.
探讨联苯胺试验及相关试剂对血痕DNA分析的影响。
采集970份含1μL静脉血的血痕滤纸样本，其中10份作为对照样本。经联苯胺试验及相关试剂处理后，采用Chelex-100法和硅珠法对960份样本进行DNA提取，然后用AmpFℓSTR™ Identifiler™ Plus PCR试剂盒进行复合扩增。比较不同组STR分型结果。
联苯胺试验后立即提取DNA。硅珠法共检测到STR位点（3.80±1.34）个，而Chelex-100法未获得STR位点。联苯胺试验后干燥处理获得完整STR分型结果的样本有13份（21.7%），硅珠法获得的STR位点数（12.90±1.49）明显高于Chelex-100法（4.70±1.96）（P<0.05）。加入冰醋酸后立即提取DNA，硅珠法获得的STR位点数为（9.40±2.09）个，而Chelex-100法未获得STR分型结果。干燥后仅加入冰醋酸、仅加入四甲基联苯胺醇溶液或3%过氧化氢溶液均可获得全部15个STR位点。
联苯胺试验对血痕DNA分析有显著影响。Chelex-100法不适用于联苯胺试验后血痕的DNA提取。联苯胺试验后干燥处理及硅珠法可有效增加血痕的STR位点数。
