Developmental validation of a novel lateral flow strip test for rapid identification of human blood (Rapid Stain Identification™-Blood)

Human blood is the body fluid most commonly encountered at crime scenes, and blood detection may aid investigators in reconstructing what occurred during a crime. In addition, blood detection can help determine which items of evidence should be processed for DNA-STR testing. Unfortunately, many common substances can cause red-brown stains that resemble blood. Furthermore, many current human blood detection methods are presumptive and prone to false positive results. Here, the developmental validation of a new blood identification test, Rapid Stain Identification™-Blood (RSID™-Blood), is described. RSID™-Blood utilizes two anti-glycophorin A (red blood cell membrane specific protein) monoclonal antibodies in a lateral flow strip test format to detect human blood. We present evidence demonstrating that this test is accurate, reproducible, easy to use, and highly specific for human blood. Importantly, RSID™-Blood does not cross-react with ferret, skunk, or primate blood and exhibits no high-dose hook effect. Also, we describe studies on the sensitivity, body fluid specificity, and species specificity of RSID™-Blood. In addition, we show that the test can detect blood from a variety of forensic exhibits prior to processing for DNA-STR analysis. In conclusion, we suggest that RSID™-Blood is effective and useful for the detection of human blood on forensic exhibits, and offers improved blood detection when compared to other currently used methods.     

不同家禽红细胞悬液对禽流感血清抗体检测的影响

为探讨不同家禽红细胞对禽流感血清抗体检测的影响,对不同家禽的禽流感阳性血清分别经不同方法处理后,做了一系列对比试验。结果发现,经受体破坏酶(RDE)处理后,虽然可以消除异种家禽血清对异种家禽红细胞的非特异性凝集作用的影响,但因处理复杂,费用高,不宜推广应用;经鸡红细胞吸附处理,可明显降低水禽血清对异种红细胞的非特异性凝集作用,但处理费时;而用水禽红细胞检测同种水禽的禽流感血清抗体,可以有效去除血清非特异性凝集的影响,且更能准确地反映水禽经禽流感疫苗免疫后的抗体水平。因而,应选用与宿主来源相同的红细胞悬液检测水禽禽流感血清抗体。     

基于紫外可见积分球反射光谱法鉴定血痕经历时间

目的建立一种快速鉴定血痕陈旧度的方法。方法在实验室条件(20℃、25℃、30℃)下,使用UV-2450型紫外可见分光光度计,利用反射附件ISR-240A积分球,以BaSO_4标准白板做参比,间隔一定时间测定健康人耳静脉血血痕纱布的反射光谱,采集特定波长反射率R_(541)、R_(577),计算R_(541)/R_(577)值,使用SPSS 17.0软件进行直线拟合与回归分析。结果一定条件下8 h内,血痕经历时间与其特定波长紫外可见反射率比值回归分析的R~2均大于0.8,回归方程成立,血痕经历时间与R_(541)/R_(577)值具有高度相关性。结论所建立的方法简便、快速、无损,可靠性好,可以对实验室条件下8 h内血痕经历时间进行鉴别。     

含硒型牛副伤寒活疫苗免疫持续期的试验

用 2批含硒型牛副伤寒活疫苗 (2 0 0 10 1,2 0 0 2 0 1)分别免疫牦牛 ,在免疫后第 7、30、6 0和90d采血 ,进行了血硒含量及血清抗体的检测。结果显示 ,这 2批疫苗免疫牦牛后 ,血硒浓度在0 .0 5 μg/mL以上可维持 90d ,第 7d可产生坚强的免疫应答。在免疫后 6个月和 13个月攻毒 ,均产生 10 0 %的保护。试验表明 ,含硒型牛副伤寒活疫苗对牦牛的免疫保护持续期至少为 12个月。     

血液中乙醇检测结果的法医学分析

目的对交通事故中血液中乙醇检测结果进行法医学分析。方法从检测方法、血液采集方法、采集时间、血液保存、尸体腐败、饮酒量与血液中乙醇质量浓度关系等方面进行血液中乙醇检测结果的法医学分析。结果检测方法、血液采集方法、采集时间、血液保存、尸体腐败等因素直接影响血液中乙醇检测结果。结论为保证交通执法的公正性，对血液中乙醇检测结果应当作法医学分析。     

死后血浆和溶血样本中IgE的稳定性

目的探究死后血浆和溶血样本中免疫球蛋白E(immunoglobulin E,IgE)经过不同保存条件及冻融处理后的稳定性。方法选取39例死后48h内非冷冻尸体的心血样本,其中20例取血浆样本,19例取全血制成溶血样本。将样本置于-20℃、4℃、25℃条件下保存28d及-80℃条件下保存1年以探究IgE在不同保存条件下的稳定性。利用5次反复冻融处理样本探究死后血浆及溶血样本IgE的冻融稳定性。应用电化学发光法检测处理前后血浆和溶血样本中IgE的浓度。结果血浆样本中IgE在-20℃、4℃、25℃3种保存条件下的降解率接近,28d后降解率均值在15%左右,相同条件下溶血样本中IgE降解速度快于血浆(P<0.05),并且在25℃条件下降解率高于另外两种(P<0.05)。血浆样本于-80℃冷冻保存1年后的浓度与冷冻前相比差异无统计学意义(P>0.05),而溶血样本在-80℃冷冻保存1年后浓度有所降低(P<0.05)。死后血浆和溶血样本在反复冻融5次后检测结果与冻融前相比差异无统计学意义(P>0.05)。结论死后血浆及溶血样本中IgE具有良好的冻融稳定性。IgE在死后血浆样本中的稳定性优于溶血样本,因此在实际案例中建议及早分离血浆保存待测。     

UPLC-MS/MS法同时检测全血中16种除草剂

目的建立全血中16种除草剂的超高效液相色谱-串联质谱(UPLC-MS/MS)同时检测方法,为除草剂中毒案事件及其他刑事案件血液中该16种除草剂的检验鉴定提供依据。方法取200μL的血液,加入800μL乙腈-水(体积比80/20),进行蛋白沉淀后,采用Acquity BEH C18(2.1mm×100mm,1.7μm)色谱柱,以水(5mmol/L的甲酸铵,0.1%的甲酸)-乙腈为流动相进行梯度洗脱,采用电喷雾离子源(ESI)、多反应监测(MRM)正离子模式对16种化合物进行检测。结果在1~200ng/mL范围内线性关系良好,R2均大于0.996;基质效应(ME%)为85.2%~104.4%,相对标准偏差(RSD%)为0.72%~4.84%;仪器检出限(IDLs)为0.2~2 ng/mL(信噪比S/N≥3),方法检出限(MDLs)为0.5~3ng/mL(信噪比S/N≥3),最低定量限(LOQs)为1~7ng/mL(信噪比S/N≥10)。结论本实验建立的全血中16种除草剂同时检验方法,前处理简便快捷、回收率高、精密度好、方法检出限低,可作为该16种除草剂中(投)毒案件的检验方法。     

基于miRNA相对表达量自动判别月经血和外周血

目的探索有效区分月经血和外周血的miRNA最优标记组合及最佳分类模型,并构建简便快速的自动化判别软件。方法对10种miRNA(miR-451a、miR-205-5p、miR-203a-3p、miR-214-3p、miR-144-3p、miR144-5p、miR-654-5p、miR-888-5p、miR-891a-5p、miR-124-3p)在200余份月经血和外周血样本中的相对表达量以实时荧光定量PCR检测,并以7种算法模型(核密度估计、K-最近邻、逻辑回归、线性判别分析、支持向量机、神经网络、随机森林)进行数据分析,选出鉴别效果最好的标记组合及算法模型,进而构建自动判别软件。结果月经血和外周血中差别最大的三种miRNA为miR-205-5p、miR-203a-3p和miR-214-3p,使用miR144-5p与上述miRNA中的一种或两种组合可达较好区分效果,其中基于miR-144-5p、miR-203a-3p和miR205-5p所形成的“最优特征项组合一”稳健性最强。7种算法模型中最佳分类模型为核密度估计模型,其次为逻辑回归模型。结论本研究建立的自动判别软件界面友好、使用简单,适合辅助法医检验关于月经血和/或外周血判别分析的计算,便利于法医物证工作,有较大的推广应用价值。     

Evaluation of a Visualization Assay for Blood on Forensic Evidence

In forensics, bloodstains on dark fabrics might be invisible for the naked eye. Although several visualization, presumptive, and confirmatory blood tests have been developed, all have one or more disadvantages, especially on DNA analysis. We report here the use of a visualization assay that can visually detect blood drops up to 1/20 dilution. In this assay, the fabric is placed between two wet filter papers and covered by glass surfaces on both sides. Pressure is applied on the glass surfaces in which bloodstains transfer onto the filter papers through capillary forces. Detected stains can be tested with other more sensitive presumptive blood tests performed on the filter paper. Even more, DNA analysis can be performed on the transferred bloodstains. The presented visualization assay is easy to perform, extremely cheap, requires little hands on time, and does not affect bloodstain pattern analysis.     

Fatal Intoxication with Methoxetamine

Methoxetamine (MXE) is a new synthetic drug of abuse structurally related to ketamine and phencyclidine. A case of a 29-year-old male with acute toxicity related to the analytically confirmed use of MXE is reported. The man was found dead at his residence. Biological material was analyzed using liquid chromatography–tandem mass spectrometry. The concentration of MXE in urine of the deceased was 85 μg/mL. Despite the vial containing the blood sample being destroyed during transportation and the blood leaking out into the cardboard packaging, the blood level of MXE was estimated. After determination of the cardboard grammage (approx. 400 g/m³) and the mean mass of the blood obtained after drying (0.1785 ± 0.0173 g per 1 mL), the estimated blood concentration of MXE was found to be 5.8 μg/mL. The high concentration of MXE in blood and urine and the circumstances of the case indicate an unintentional, fatal intoxication with this substance.