Box-Benhken响应面法优化超声提取天冬中皂苷的工艺

目的 优化天冬中皂苷的超声提取工艺,为质量检测提供基础。方法 以紫外可见分光光度法测定天冬中皂苷的含量,并比较菝葜皂苷元与薯蓣皂苷元对照品与天冬样品的最大吸收波长,采用单因素实验法及Box-Benhken响应面法设计天冬皂苷的超声提取实验,并对Box-Benhken响应面模型进行方差分析。结果薯蓣皂苷元的最大吸收波长与天冬样品最大吸收波长相近。响应面分析的最佳提取条件为：乙醇浓度为48%,液料比为50 mL/g,超声时间为61 min。天冬皂苷的含量预测值为5.10%,验证试验的天冬皂苷含量的平均值为5.07%。结论 选择薯蓣皂苷元作为对照品,可以较好地反映天冬皂苷含量水平。响应面法建立的天冬皂苷含量模型具有良好的实际指导意义,可作为进一步研究天冬的实验基础。     

Box-Behnken响应面设计法优化排脓散水提工艺

目的 优选排脓散最佳水提工艺。方法 采用Box-Behnken响应面设计法,以水提液中3个指标性成分（柚皮苷、新橙皮苷、芍药苷）的含量和出膏率的综合评价作为考察指标,考察料液比、浸泡时间、提取时间3个因素对提取工艺的影响。结果 排脓散水提的最佳工艺条件为15倍水,浸泡67 min,提取74 min。结论 Box-Behnken实验设计法优化排脓散的水提工艺方法可行,预测性较好。     

多指标正交试验优选苓桂术甘颗粒水提工艺

目的 优选苓桂术甘颗粒的水提工艺。方法 采用正交试验对水提工艺进行优化,以桂皮醛转移率、甘草酸转移率和干膏得率为评价指标,考察加水量、煎煮时间、煎煮次数对提取工艺的影响。结果 最佳提取工艺为加8倍量水,提取3次,每次煎煮1 h。结论 多指标加权考察水提工艺,既符合中药复方的复杂性,又能合理反映水提效果。该水提工艺设计合理,可为苓桂术甘颗粒的研制提供理论和试验基础。     

构树皮总黄酮提取及抗菌活性研究

目的 提取构树皮有效的抑菌活性部位。方法 采用正交试验法优化构树皮黄酮最佳超声提取工艺,并采用AB-8大孔吸附树脂富集构树皮总黄酮提取物活性部位,用平皿药基法比较不同部位的抑菌效果。结果 构树皮总黄酮的最佳提取工艺为：以10倍体积的70%乙醇为溶剂,超声提取20 min,功率300 W。经AB-8大孔吸附树脂富集分离后,70%乙醇洗脱部位对浅部真菌红色毛癣菌和白色念珠菌均有良好的抑制作用。结论 所采用的工艺操作简单、耗能低、总黄酮提取率高,抑菌作用强。     

正交试验法优选桃红四物汤的水提工艺

目的 优选桃红四物汤的水提工艺。方法 以芍药苷和浸膏得率为考察指标,以加水量、提取时间、提取次数为考察因素,采用正交试验优选桃红四物汤的最佳水提工艺。结果 桃红四物汤的最佳水提工艺为加12倍量水提取3次,每次1.5 h。结论 优选出的桃红四物汤的水提工艺合理,可为其工业化生产提供依据。     

DNA Purification Cell Lysis and Wash Step Modifications for Low-Template DNA Sample Processing,

As DNA technology becomes increasingly sensitive, forensic laboratories are receiving more low-template DNA samples. These samples, already low in DNA content, become even more challenging to process as the available DNA becomes further reduced during the extraction step. In this study, two extraction modifications were tested to determine if the cause of DNA loss could be identified and mitigated. A double lysis technique was used to test for DNA loss in the sample collection substrate, and lysate eluates were re-extracted to determine DNA loss from inefficient binding to the silica column. Both modifications showed DNA was lost at these steps. However, resulting STR profiles from these samples had fewer peaks and lower peak heights when compared to samples processed with no extraction modifications. Overall, the potential benefits of adding these extraction modifications for low-template DNA sample processing are not enough to justify the risk associated with additional manipulation.     

Experimental long-distance haplotyping of OCA2-HERC2 variants

The regulatory HERC2 SNP, rs12913832, is strongly associated with blue and brown eye colour. However, eye colour in heterozygous rs12913832 individuals is observed to vary greatly. Missense mutations in OCA2, such as rs1800407 and rs74653330, are associated with lighter eye colour in some but not all heterozygous rs12913832 individuals. Determining the physical linkage of these variants might help to further explain eye colour variation. So far, experimental haplotyping of these variants has been challenging because the genomic distance between them (∼ 135 kb) exceeds the fragment lengths produced by commonly used DNA isolation kits. The aim for this study was to explore novel methods for long distance haplotyping to assess associations between OCA2-HERC2 haplotypes and eye colour. DNA was isolated from frozen blood samples collected from Norwegians that are known to be heterozygous for both HERC2 rs12913832 and OCA2 SNPs, either rs1800407 (n = 23) or rs74653330 (n = 17), using the newly commercially available Monarch® HMW (heigh molecular weight) DNA Extraction Kit (New England BioLabs_inc). We successfully isolated DNA fragments up to 210 kb, which were long enough to haplotype OCA2-HERC2 loci by droplet digital PCR (ddPCR). Three haplotypes were observed in the study population: rs12913832:A-rs1800407:T in 22/23 individuals, rs12913832:A-rs1800407:C in 1/23 individuals and rs12913832:A-rs74653330:T in 16/16 individuals. As expected, all individuals with the rs12913832:A-rs74653330:T haplotype had intermediate to blue eye colour. However, the rs12913832:A-rs1800407:T haplotype was observed in both blue and brown-eyed individuals, suggesting more research is needed.     

Expedited, chemically enhanced sperm cell recovery from cotton swabs for rape kit analysis

This report focuses on the development of a method for chemically induced enhancement of cell elution and recovery from cotton swabs. The method exploits the exclusive use of detergents for intact cell removal, and can be utilized in conjunction with, or to circumvent, conventional differential extraction (DE). Samples treated with Sarkosyl (54.4 +/- 1.8%) and sodium dodecyl sulfate (SDS) (78.5 +/- 0.7%) yielded higher sperm cell recoveries than a conventional DE buffer (39.4 +/- 2.1%). The results indicated that the choice of detergent affected sperm cell yield, with anionic detergents having the greatest effect. Storage time of samples affected the concentration of detergent required for optimal sperm cell recovery, longer times requiring increased detergent concentrations. In addition, the extent of sperm cell lysis by proteinase K digestion was evaluated. The results indicate that the exclusive use of SDS enhances the release of sperm and epithelial cells from a cotton swab as compared with DE buffer, providing for a more effective DNA analysis.     

Development of a quantitative LC-MS/MS method for the analysis of common propellant powder stabilizers in gunshot residue

In traditional scanning electron microscopy/energy dispersive X-ray analysis of gunshot residue (GSR), one has to cope more and more frequently with limitations of this technique due to the use of lead-free ammunition or ammunition lacking heavy metals. New methods for the analysis of the organic components of common propellant powder stabilizers were developed based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). A multiple reactions monitoring scanning method was created for the screening of akardite II, ethylcentralite, diphenylamine, methylcentralite, N-nitrosodiphenylamine, 2-nitrodiphenylamine, and 4-nitrodiphenylamine, present in standards mixtures. Five out of seven of these target compounds can be selectively identified and distinguished from the two others with a high accuracy. Samples from the hands of a shooter were collected by swabbing and underwent solid phase extraction prior to analysis. Detection limits ranging from 5 to 115 mug injected were achieved. Results from several firing trials show that the LC-MS/MS method is suitable for the detection of stabilizers in samples collected following the firing of 9 mm Para ammunitions.     

2种陈旧骨骼、牙齿DNA纯化方法的比较

目的比较有机法+QIAquick纯化法和DNA IQ磁珠法对陈旧骨骼和牙齿DNA的纯化效果。方法选择10份陈旧骨骼和12份牙齿样本,进行消化后分别采用有机法+QIAquick纯化法和DNA IQ磁珠法进行提取纯化,进行DNA定量后用SinofilerTM试剂盒进行检测。结果 2种方法纯化的骨骼、牙齿DNA的IPC CT值无显著差异。有机法+QIAquick纯化法纯化的骨骼、牙齿DNA平均浓度分别为0.180ng/μL±0.068ng/μL和0.132ng/μL±0.027ng/μL,所有样品均获得全部基因分型。DNA IQ磁珠法纯化的DNA平均浓度分别为0.038ng/μL±0.028ng/μL和0.036ng/μL±0.007ng/μL,有5份骨骼和6份牙齿样本仅获得部分基因分型或未能分型。结论有机法+QIAquick纯化法对陈旧骨骼、牙齿DNA的纯化效果优于DNA IQ磁珠法。