Amsterdam UMC, University of Amsterdam, Biomedical Engineering & Physics, Meibergdreef 9, Amsterdam, The Netherlands.
Amsterdam UMC, University of Amsterdam, Biomedical Engineering & Physics, Meibergdreef 9, Amsterdam, The Netherlands.; Co van Ledden Hulsebosch Center (CLHC), University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
Forensic Sci Int Genet. 2021 May;52:102485. doi: 10.1016/j.fsigen.2021.102485. Epub 2021 Feb 15.
Immunolabeling is a technique, which has recently been introduced to enhance the quality of developed fingermarks and subsequently strengthen the evidential value. The effect of this method on subsequent DNA analysis, however, has not been explored yet. Therefore, the current pilot study aimed to determine whether STR profiling is possible after immunolabeling. Since immunolabeling involves washing steps which could reduce DNA quantities, the use of different fixatives including methanol, formaldehyde and universal molecular fixative (UMFIX) were investigated. STR profiles from the (immunolabeled) fingermarks were generated after four days and four weeks by a direct PCR method to enable comparison of relatively fresh and old fingermarks. The fingermarks were deposited on diverse forensically relevant substrates, including glass, metal and tile. STR profiles could be recovered for all tested fixatives with no significant difference in performance. However, the mean number of detected alleles was the highest when methanol was used for fixation. Furthermore, immunolabeling on aged fingermarks (4 weeks) was also possible, but the number of detected alleles showed a non-significant decrease. DNA could be recovered from deposits on all substrates, of which glass showed the highest mean number of detected alleles followed by metal and tile.
免疫标记技术是一种最近引入的技术，用于提高已显指纹的质量，从而增强其证据价值。然而，这种方法对随后的 DNA 分析的影响尚未得到探索。因此，目前的初步研究旨在确定免疫标记后是否可以进行 STR 分析。由于免疫标记涉及可能减少 DNA 数量的洗涤步骤，因此研究了不同的固定剂，包括甲醇、甲醛和通用分子固定剂（UMFIX）。通过直接 PCR 方法，在免疫标记后的第 4 天和第 4 周生成了（免疫标记的）指纹的 STR 图谱，以便比较相对新鲜和陈旧的指纹。指纹被沉积在多种法医相关的基质上，包括玻璃、金属和瓷砖。所有测试的固定剂都可以恢复 STR 图谱，性能没有显著差异。然而，当使用甲醇固定时，检测到的等位基因数量最高。此外，对陈旧的指纹（4 周）进行免疫标记也是可能的，但检测到的等位基因数量没有显著减少。可以从所有基质上的沉积物中回收 DNA，其中玻璃显示出最高的平均检测到的等位基因数量，其次是金属和瓷砖。
