Thong Zhonghui, Wee Audrey Ping Jue, Heng Baoqiang, Syn Christopher Kiu Choong
DNA Profiling Laboratory, Biology Division, Health Sciences Authority, 11 Outram Road, Singapore 169078, Singapore.
Genes (Basel). 2025 Sep 12;16(9):1073. doi: 10.3390/genes16091073.
The acid phosphatase (AP) test is widely utilised in forensic biology laboratories to examine for the presence of semen on crime evidence. If semen is present, the AP-positive areas are marked on the exhibit to indicate the precise location of the semen stain. However, documenting AP-positive areas with a crayon is time-consuming and laborious. In this proof-of-concept study, we evaluated the use of Saral Wax-Free Transfer Taper (TP) as an alternative tool for tracing the boundaries of AP-positive areas. We demonstrated that the TP pigment did not inhibit PCR amplification, as indicated by consistent internal PCR control (IPC) C values during real-time DNA quantification. While a reduction in DNA yield was observed under stress-test conditions, where TP pigment was intentionally included in the samples, complete STR profiles were still recovered with no allele dropout. Importantly, the documenting time for AP mapping was reduced by approximately five-fold with TP compared to crayon, underscoring its potential to enhance efficiency in forensic laboratory workflows.
酸性磷酸酶（AP）检测在法医物证实验室中被广泛用于检查犯罪证据上是否存在精液。如果存在精液，会在证物上标记出AP阳性区域，以表明精液污渍的精确位置。然而，用蜡笔记录AP阳性区域既耗时又费力。在这项概念验证研究中，我们评估了使用Saral无蜡转移蜡笔（TP）作为描绘AP阳性区域边界的替代工具。我们证明，如实时DNA定量过程中一致的内部PCR对照（IPC）C值所示，TP色素不会抑制PCR扩增。虽然在压力测试条件下观察到DNA产量有所下降，即在样本中故意加入了TP色素，但仍能完整地获得STR图谱，且没有等位基因缺失。重要的是，与蜡笔相比，使用TP进行AP绘图的记录时间减少了约五倍，这突出了其在法医实验室工作流程中提高效率的潜力。
