新型指纹显现膜的研制和在指纹显现中的应用

JLGW系列指纹显现膜以传统茚三酮为显色剂,以压敏型乳化物为显色剂包夹介质制成现场指纹显现膜。现已成功地对多种客体上的潜在汗液指纹和血指纹进行显现。使其应用范围由原来的渗透性客体扩展到非渗透性客体。对一些无法利用化学法显现的疑难客体(皮革、热敏纸)也取得成功。对氨基酸显色灵敏度大于0.01%,潜血指纹显现灵敏度大于30%(V/V)。     

SWP荧光剂熏显油脂手印方法的初步研究

目的建立SWP荧光剂熏显油脂手印的新方法。方法选取12中常见客体,根据试验需要分别捺印油脂手印144枚和油汗混合手印100枚,用多功能手印显现柜加热升华SWP荧光剂,熏显渗透性和非渗透性客体上的手印。结果油脂手印显现出了142枚,显出率达到98．6％;油汗混合手印,非渗透性客体共显出100枚,显出率达到100％,渗透性客体共显出95枚,显出率达到95％。结论SWP荧光剂对油脂手印的显现效果良好,可与“502”同时熏显,且不影响茚二酮等其他方法的进一步检验。     

一种改进的碘熏法-碘锌手印显现法

目的为解决传统碘熏法显出手印容易褪色、固定困难等问题。方法提出了一种改进的碘熏法-碘锌手印显现法，实验了不同反应物配比、不同客体材质对显现效果的影响；与常规碘熏法进行了对比实验；并考察了碘锌法显出手印的稳定性。结果碘锌手印显现法可以用于常见渗透性及非渗透性客体上新鲜汗潜手印的显现。该方法不必外加热源，携带、存储和应用更加便利；该方法显出的指纹纹线保存时间与传统碘熏法相比明显延长。结论碘锌手印显现法是一种高效、实用的手印显现方法。     

“502”加膜一染色法显现油质手印

目的探索方便快捷并有效的油质手印显现方法。方法用“502”熏显常见玻璃、粗糙皮革等不同客体上不同遗留时间的油汗手印和多油手印,加染后用透明胶带粘取。结果显现了30天左右大多数非渗透性客体上的油质加层手印,10天左右渗透性客体上的油质渐层手印。结论本方法适用于油质加层手印及部分油质渐层手印的显现,显出手印清晰,流畅,不破坏手印。     

荧光黄湿粉显现手印方法的初步研究

目的研发一种具有荧光特性的黄湿粉,以提取遗留在不同客体上的不同种类的手印。方法在100mL温水中加入适量的表面活性剂,溶解后加入100g荧光黄颜料,选用不同种类客体及不同种类物质手印进行显现实验,比较显现效果;结果遗留在光滑非渗透性客体及半渗透性客体表面的汗潜、油潜手印,显出的手印纹线流畅、反差强、荧光强;结论荧光黄湿粉可适用于光滑非渗透性客体及半渗透性客体表面新鲜或较新鲜汗潜手印、油潜手印及血潜手印的显现。     

氨基黑显现常见客体上潜血足迹研究

目的研究氨基黑显现潜血足迹所适用的常见客体。方法选择14种常见客体,制作潜血足迹样本,用氨基黑进行显现。结果浅色非渗透性客体的效果优于其他客体。结论氨基黑可以很好的显出某些渗透性客体和非渗透性客体表面的潜血足迹。     

真空镀膜与“502”熏显法显现非渗透性客体上汗潜手印的比较研究

目的探索真空镀膜手印显现技术,提高现场潜在手印显现率。方法通过真空镀膜与＂502＂熏显法显现常见非渗透性客体上汗潜手印的对比实验,比较二者显现效果优劣。结果真空镀膜法对于显现常见非渗透性客体上的新鲜和陈旧汗潜手印都有着明显的优势。结论真空镀膜是一种更为灵敏的非渗透性客体手印显现方法,是现有手印显现方法的重要补充。     

液体镀膜显现指纹法

真空镀膜技术显现指纹曾被广泛应用,然而此项技术操作复杂,价格昂贵,逐渐被人们所淘汰。本文介绍一种液体镀膜显现指纹的方法,它具有操作简便、易行,所需药品为常用药剂。对玻璃、陶瓷、塑料等非渗透性客体表面的新鲜和陈旧汗液,油泥、油、血指纹以及灰尘指纹(在先采用固定剂固定后)都有较好的效果,尤其是处理从水中捞出的客体上的指纹或客体表面潮湿,用常规方法无法显现时,用此方法能显出图像细腻、纹浅清晰、特征准确的高质量指纹。     

上转换发光微粒悬浮液显现手印技术初探

目的 建立NaYF4∶Er,Yb微粒悬浮液显现手印技术方法并界定适用范围与条件.方法 用NaYF4∶Er,Yb微粒悬浮液显现瓷砖、玻璃等19种（各50枚）不同客体上皮脂汗手印,并对结果进行分析比较.结果 该方法对背景复杂的非渗透性客体上的油汗手印显现良好,其效果优于普通ZnO小颗粒悬浮液.结论 该方法操作简便、适用客体广泛、背景干扰少,适合进一步研究推广.     

茚三酮固体介质法显现不同纸张表面潜指纹

茚三酮是显现渗透性客体上潜在汗液手印的最常用方法之一,采用微量物证提取纸和茚三酮溶液有机结合制作的茚三酮固体介质可以有效避免客体表面背景着色,不容易引起纸张油墨扩散,另外避免使用的溶剂易燃。能够更便捷的显现现场指纹,并且能够突破茚三酮只能显现渗透性客体的局限,拓宽茚三酮显现客体的范围,在热敏纸上潜指纹的显现方面有独特的应用优势。     

汗潜指印的STR分型检测

目的探索汗潜指印的荧光STR复合扩增检测的方法。方法采用Chelex-100和Microco-100浓缩柱,提取汗潜指印中DNA,STR复合扩增荧光电泳检测。结果 105例汗潜指纹STR分型可明确判读5个以上基因座的占30.3％,个体之间的差异、捺印指印时用力大小以及指印遗留在客体上时间的长短均影响检测成功率。结论该汗潜指印的DNA提取方法步骤简单,方法较为稳定,使单枚汗潜指印可望获得DNA分型。     

胶带粘面手印荧光显现剂的研发与应用

目的根据胶带粘面上潜在手印的特点,利用染料和潜手印的理化性质,研究开发胶带粘面手印荧光显现剂。方法在各种胶带粘面上显现潜在手印,并与常规的碳素墨水染色法进行比较。结果在长波紫外线照射下手印呈黄色明亮荧光,手印纹线清晰、连贯,基本不受手印遗留时间、客体表面颜色和性质的影响。结论胶带粘面上的汗潜手印和血潜手印用荧光显现剂显现效果优于碳素墨水染色法,在实际案件的侦破中有较好的应用前景。     

血手印显现的实验研究

目的 提出了采用荧光显现试剂显现血手印的新方法。方法 在比较使用联苯胺及其衍生物显现血手印的同时,实验了通过强氧化剂破坏血红素、沉淀珠蛋白,采用激活血痕、蛋白染色的方法,使血手印清晰显出。结果 显现效果不受客体表面颜色的影响,不受血手印遗留时间的影响。结论 适用客体范围广,灵敏度高。     

短波紫外照射对汗潜手印DNA检测的影响初探

目的探测短波紫外灯的照射是否会对汗潜手印DNA检测产生影响。方法由每名志愿者在纸张上捺印4枚拇指指印使每枚指印的脱落细胞量保持基本相同,抽取每名志愿者所捺印的一枚指印作为一组,共有四组,将三组指印置于短波紫外灯的照射下,照射时间分别设置为10min﹑30min和1h,还有一组不照射,然后用磁珠法对所有指印提取DNA并进行定量。结果短波紫外灯的照射会对汗潜手印中的DNA造成减损,照射时间越长,减损得越多。结论尽量减少短波紫外灯对汗潜手印照射的时间(可控制在10min内),以保证汗潜手印有足够量的DNA而能被用于STR分型检测。     

The thermodynamics of latent fingerprint corrosion of metal elements and alloys

Redox reactions taking place between the surface of a metal and fingerprint residue have been expressed thermodynamically in terms of both the Nernst equation for reduction potential and the complexation constant for the formation of complex metal halide ions in aqueous solution. These expressions are used to explain experimental results for the corrosion of 10 different metal elements by fingerprint residue in air at room temperature. Corrosion of noble metals, such as silver and gold, supports the proposition that the degree of metal corrosion is enhanced by the presence of chloride ions in eccrine sweat. Extending the experiments to include 10 metal alloys enabled the construction of a fingerprint corrosion series for 20 different metals. Fingerprint corrosion on metals alloyed with > approximately 40% copper was found to display third level fingerprint detail. A comparison of both conventional ink on paper and digital (Livescan) fingerprinting techniques with fingerprints deposited on 9 Karat gold alloy has shown that gold alloy depositions are least susceptible to third level detail obliteration by poor fingerprint capturing techniques.     

汗潜指印DNA提取方法的初步研究

目的建立渗透性载体及非渗透性载体上汗潜指印DNA的提取和检验方法。方法采用C-有-柱法及SiO2法两种DNA提取方法,PCR扩增后310型遗传分析仪检测。结果载玻片上3枚汗潜指印采用2种方法均可扩增出Amel及9个STR位点;纸上3枚汗潜指印用SiO2法检见Amel及9个STR位点,而用C-有-柱法检验结果不稳定。渗透性及非渗透性载体上1及2枚汗潜指印,采用上述两种DNA提取方法,检验结果均不稳定。结论所建立的方法可以检见渗透性及非渗透性载体上汗潜指印DNA,并达到同一认定的程度。     

蜡质客体上汗潜手印的显现

目的建立蜡质客体上汗潜手印的显现方法;方法遗留在蜡质客体上的汗潜手印,经适量“502”熏显后,用较高浓度的BBD溶液进行染色,在多波段光源的激发下以增强显现效果。结果遗留在蜡面上10天以内的汗潜手印可得到理想结果;结论该方法方便易行,并成功用于检案。     

Toward multidimensional information: A derivatization-free UHPLC-QqQ MS/MS method for amino acid components of fingerprint

The analysis of fingerprint chemical composition is a meaningful way to excavate the multidimensional information of fingerprint, including the donor profiling information and the age of a fingerprint, which broadens the evidential values of fingerprint, especially for the partial and distorted fingerprint. But the research remains still in the pilot phases or is ongoing. Amino acids are the dominant organic substances in latent sweat fingerprint and influenced by many donor factors. Hence, their content reflects personal information of donors. Forensic science will be revolutionized if suspects can be individualized by their amino acid content. The diverse nature, distinct physicochemical properties, and ultra-micro levels of amino acids present in fingerprints make it hard to detect. A high sensitivity method for detecting and quantifying multiple amino acid components is required. UHPLC-QqQ MS/MS offers high sensitivity, high separation, simultaneous multicomponents detection, and no derivatization, making it an ideal method for detecting and analyzing amino acids in fingerprints. Therefore, in this study, we propose and validate an efficient UHPLC-QqQ MS/MS method for the extraction and analysis of 13 amino acids from fingerprint. We compared the results of amino acids of 10 different substrates and found that the inherent amino acids in most porous substrates would have been extracted along with the fingerprint amino acids, making them unsuitable for quantitative amino acid analysis. Instead, plastic sheets are ideal substrates for laboratory studies. Then, extensive experiments were conducted among 30 donors for multidimensional information analysis. The type of samples analyzed were eccrine-rich fingerprints. A Binary Logistic Regression (BLR) model was developed, and the female and male donors were successfully differentiated by amino acids in fingerprints. Two other mathematical models were also developed to verify the accuracy, and all three different mathematical models were able to identify donors of different genders with over 90% accuracy. This demonstrates that amino acids have the potential to provide more information for donors as metabolic markers. In the future, we will conduct a series of experiments to analyze more multidimensional information for individual identification by amino acid content in the fingerprint.     

Separation of visibly-excited fluorescent components in fingerprint residue by thin-layer chromatography

The use of lasers for the detection of fingermarks is widespread in the forensic field. Despite this, and the fact that many studies have been conducted into the composition of fingermark residue, the components responsible for the inherent visible fluorescence remain unidentified. Traditionally compositional studies have been performed on sweat, sebum, or skin surface washes, none of which are truly representative of the situation when a fingerprint is deposited on a surface. In this paper thin-layer chromatography (TLC) has been performed on sebum-rich fingermarks laid directly onto TLC plates and an argon ion laser used to visualize the separated components. It has been found to be a robust and reproducible method for studying the fluorescent components in fingermark residue and is considered to be more realistic than other methods of sample preparation as it eliminates the chances of extraneous matter being extracted from the skin surface. Investigations into the nature of the separated compounds have also been made and the results are reported.     

物理显影液显现汗潜手印的再研究

目的进一步探讨物理显影液显现汗潜手印的适用性。方法广泛分析、筛选试剂,拓宽实验内容,并采用正交实验设计法定量。结果选用富含脂肪醇硫酸盐的表面活性剂及适量配比优化的物理显影液显出手印效果良好、稳定。结论本文得出的物理显影液,配制较简易,成本低廉,其实用性得以有效提高。