Sherier Allison J, Kieser Rachel E, Novroski Nicole M M, Wendt Frank R, King Jonathan L, Woerner August E, Ambers Angie, Garofano Paolo, Budowle Bruce
Center for Human Identification, UNT Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA.
Department of Microbiology, Immunology, and Genetics, UNT Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA.
Int J Legal Med. 2020 Jan;134(1):45-54. doi: 10.1007/s00414-019-02081-6. Epub 2019 Jun 4.
The microFLOQ® Direct Swab was tested by sampling diluted blood, semen, and saliva stains deposited on cotton cloth. DNA typing was performed using the PowerPlex® Fusion 6C System by direct PCR or a modified direct PCR. Direct PCR of swabs sampled the center of a stain, compared to their respective edge samplings, and had higher profile completeness and total relative fluorescent units (RFU) for all dilutions of blood and semen stains tested. The modified direct PCR used template DNA eluted from the swab head using the Casework Direct Kit, Custom and washes either contained 1-thioglycerol (TG) additive or no TG. Modified direct PCR had mixed results for blood, saliva, and semen stains, with semen stains showing significant differences in profile completeness (5% and 1%) and total RFU (neat, 5% and 1%) with the addition of TG to the Casework Direct Reagent. No significant difference was seen in any dilution of blood or saliva stains processed with the modified direct PCR, but profile completeness and total RFU were improved overall compared to stains swabbed with cotton swabs or 4N6FLOQSwabs™. This study supports the hypothesis that the microFLOQ® Direct Swab is able to collect minute amounts of DNA from cotton cloth and may be considered as an alternate pre-screening methodology in forensic biology casework.
使用microFLOQ®直接拭子对沉积在棉布上的稀释血液、精液和唾液污渍进行采样测试。通过直接PCR或改良直接PCR,使用PowerPlex® Fusion 6C系统进行DNA分型。与各自的边缘采样相比,拭子的直接PCR对污渍中心进行采样,对于所有测试的血液和精液污渍稀释度,其图谱完整性和总相对荧光单位(RFU)更高。改良直接PCR使用从拭子头部用Casework Direct试剂盒洗脱的模板DNA,定制和洗涤液要么含有1-硫代甘油(TG)添加剂,要么不含TG。改良直接PCR对血液、唾液和精液污渍的结果不一,在Casework Direct试剂中添加TG后,精液污渍在图谱完整性(5%和1%)和总RFU(原液、5%和1%)方面显示出显著差异。在用改良直接PCR处理的任何血液或唾液污渍稀释液中均未观察到显著差异,但与用棉签或4N6FLOQSwabs™擦拭的污渍相比,图谱完整性和总RFU总体上有所提高。本研究支持以下假设:microFLOQ®直接拭子能够从棉布上收集微量DNA,可被视为法医物证学案件工作中的一种替代预筛查方法。