Diagnostic Value of TB-IGRA, PPD, TB-DNA-PCR and TB-Ab in Silicosis Complicated with Tuberculosis

Purpose: The purpose of this article is to investigate the clinical value of TB-IGRA (Tuberculosis-Interferon Gamma Release Assay), PPD (Intradermal Terbuculin Test), TB-DNA-PCR (Tuberculosis-Deoxyribonucleic-Polymerase Chain Reaction) and TB-Ab (Tuberculosis-Antibody) in diagnosing silicosis complicated with pulmonary tuberculosis. Methods: 53 cases of suspected silicosis complicated with pulmonary tuberculosis were selected in the time span ranging from February 2017 to May 2019. TB-IGRA test, PPD test, TB-DNA-PCR and TB-Ab detection were performed. The sensitivity, specificity, positive predictive value and negative predictive value were calculated. Results: Silicosis and pulmonary tuberculosis were diagnosed in 11 cases, with an incidence of 20.75%. The positive rates of TB-IGRA, PPD, TB-DNA-PCR and TB-Ab were 66.04%, 30.19%, 5.67% and 26.42%, respectively. The sensitivity was 90.91%, 81.82%, 27.27% and 54.55% respectively. The specificity was 42.86%, 80.95%, 100% and 80.95% respectively. The positive predictive values were 28.57%, 50%, 100% and 42.86% respectively. The negative predictive values were 94.44%, 91.89%, 84% and 87.18%. The positive rate, sensitivity and negative predictive value of TB-IGRA were the highest, while the specificity of TB-DNA-PCR was the highest yet with low positive rate, sensitivity and positive predictive value. Conclusion: The positive rate and sensitivity of TB-IGRA were high, yet with poor specificity, so it was impossible to judge whether the cases belonged to active pulmonary tuberculosis. The combination of PPD and TB-DNA-PCR could improve the sensitivity, specificity and positive predictive value, and the diagnostic accuracy of active pulmonary tuberculosis, which showed satisfactory clinical value.

慢性肾衰患者并发结核病的诊断结核菌DNA-PCR与抗PPD-IgG的比较

慢性肾衰患者的结核病发生率高，肺外结核多见，缺乏特异的临床表现，故诊断较为困难。本研究检测了１１例慢性肾衰并发结核患者的血中结核菌ＤＮＡ－ＰＣＲ和血清抗ＰＰＤ～ＩｇＧ（ＥＬＩＳＡ），并检测了其中５例患者的渗出液（肺、腹水）及排泄物（尿，痰），结果表明，在血中，抗ＰＰＤ－ＩｇＧ的阳性率明显高于结核菌ＤＮＡ－ＰＣＲ，在渗出液或排泄物中，二者的阳性率大致相同．提示在尿毒症患者这一特定的人群中，血清或渗出液（排泄物）中抗ＰＰＤ－ＩｇＧ的检测对诊断结核有重要意义。

TB-DNA-PCR阳性意义的再认识

TB-DNA-PCR阴阳性的判定标准与阳性意义的认识有不同的观点,本文拟对此结合作者自己的临床经验加以论述,与大家共同探讨。

Diagnostic Value of TB-IGRA, PPD, TB-DNA-PCR and ADA in Tuberculous Pleural Effusion

Objective: To investigate the clinical diagnostic value of TB-IGRA (Tuberculosis-Interferon Gamma Release Assay), PPD (Intradermal Tuberculin Test), TB-DNA-PCR (Tuberculosis-Deoxyribonucleic-Polymerase Chain Reaction) and ADA(Adenosine Aeaminase) in tuberculous pleural effusion. Methods: 60 patients with tuberculous pleural effusion discharged from our department from January 1, 2018 to December 31, 2019 were selected. Moreover, the TB-IGRA in peripheral blood, PPD test, TB-DNA-PCR and ADA in pleural effusion were detected. Subsequently, the positive rate, negative rate, sensitivity and omission diagnostic rate of TB-IGRA, PPD, TB-DNA-PCR, ADA and combined TB-IGRA were calculated. Results: The positive rate and sensitivity of TB-IGRA, PPD,TB-DNA-PCR, and ADA were 95%, 71.67%, 5% and 86.67% respectively. The omission diagnostic rate was 5%, 28.33%, 95% and 13.33%. TB-IGRA showed the highest positive rate and sensitivity, and TB-DNA-PCR represented the highest omission diagnostic rate. The sensitivity of TB-IGRA + PPD was 98.33%, while the omission diagnostic rate was 51.67%. The sensitivity of TB-IGRA + TB-DNA-PCR was 95%, while the omission diagnostic rate was 5%. The sensitivity of TB-IGRA + ADA was 100%, while the omission diagnostic rate was 0%. In addition, the TB-IGRA + ADA had the highest sensitivity and the lowest omission diagnostic rate. Conclusion: TB-IGRA has high positive rate, high sensitivity and low omission diagnostic rate, which is superior to the traditional sputum test for tuberculosis. Notably, the combination of PPD, TB-DNA-PCR, ADA is capable of improving the diagnosis rate, and the diagnosis rate can reach 100% when combined with ADA, which is able to provide solid diagnostic value in clinical practice.

小儿咽拭子EB病毒DNA-PCR临床应用

EB病毒在人群中具有广泛的感染性,病毒传播途径主要为唾液,也可以经血液传播,大多数的初次感染发生在婴幼儿时期,多数感染后无明显症状或引起轻度咽炎和上呼吸道感染.为进一步了解EB病毒在儿童呼吸系统疾病的感染比例,作者采用小儿咽拭子EB病毒DNA-PCR随机检测300例6岁以下发生呼吸道感染的患儿,结果报告如下：

高通量测序联合DNA-PCR检测骨髓增生异常综合征患者51种血液肿瘤相关基因突变

骨髓增生异常综合征（MDS）是一类以不同程度血细胞减少、骨髓病态造血及高风险向白血病转化为特征的异质性髓系肿瘤。基因突变、基因表达失控及表观遗传学改变在MDS的发生、发展中起关键作用。

HBsAg ELISA+/HBV DNA NAT-献血者血清学与分子生物学特征分析

目的 了解西安地区无偿献血人群HBsAg ELISA检测结果与HBV DNA检测结果不一致的标本相关血清学标志物的分布情况。方法 收集2022年11月1日—2023年4月30日陕西省血液中心HBsAg ELISA+/HBV DNA NAT-(ELISA+/NAT-)标本共计71份,对其采用电化学发光法检测乙肝血清学标志物,同时复检巢式PCR扩增HBV S区和C区基因片段。结果 双ELISA+/NAT-标本(n=30)巢式PCR检测阳性率远高于单ELISA+/NAT-标本(n=41)(60%vs 24.40%,P<0.05)。前者献血者100%为初次献血者,血清抗-HBc阳性率100%,血清学模式以1、4、5此3项阳性(80%)为主;后者献血者中31.7%为重复献血者,血清抗-HBc阳性率仅为19.51%,血清学模式以单2项阳性(43.90%)和全阴(36.58%)为主。结论 单ELISA+结果存在较多假阳性,导致不必要的血液报废;而NAT-标本可能存在低水平的HBV DNA,产生漏检风险。建议针对单HBsAg ELISA+/NAT-献血者,采用多套系统多种方法追溯检测,提高献血者HBV筛查的准确度,减少不必要的血液浪费。

藜麦FLS基因家族的鉴定、表达及DNA变异分析

【目的】黄酮醇合成酶(FLS)是石竹目植物中多酚类次生代谢的关键酶,为探究FLS基因在藜麦生长发育中的功能,对FLS基因家族进行鉴定和表达分析。【方法】利用生物信息学分析网站,鉴定出CqFLS家族成员,分析其基因结构、蛋白的理化性质、二级结构、三级结构、启动子顺式元件以及系统进化关系等,并通过基因克隆、构建表达载体的方法分析其蛋白表达情况。【结果】共鉴定出3个CqFLSs基因,不均匀分布在2条染色体上,CqFLSs启动子区域包含水杨酸、脱落酸、茉莉酸甲酯和干旱诱导等元件;CqFLS2.1g发现多处InDel和SNP变异,在ch0128871893、28871125、28872881处编码核苷酸删除,且均注释为上游效应,未检测到移码突变;FLS家族系统进化树分析可知,与其他两个基因相比,CqFLS2.1g与CqFLS1.1g、CqFLS3.10g处于不同分支,表达水平也存在差异,CqFLS2.1g可能发生分化;同时,基因表达分析表明,3个CqFLSs基因在青白1号籽粒中整体表达量高于青黑1号和贡扎4号。对克隆出的CqFLS1.1g用0.3 mmol/L的IPTG诱导,在20℃和37℃的条件下均可成功表达。【结论】CqFLS1.1g在花的形成以及籽粒发育过程中发挥作用,而CqFLS2.1g则主要参与藜麦籽粒的形成,CqFLS的表达具有组织特异性,在藜麦生长发育过程中发挥重要的作用。

雅鲁藏布江中游拉萨裸裂尻鱼环境DNA检测及生物量评估

建立快速和准确的环境DNA(eDNA)检测方法,可为鱼类的长期监测提供便利,为鱼类资源保护和管理提供技术支撑。2019年在雅鲁藏布江中游干流及拉鲁湿地和茶巴朗湿地采集了20种鱼和水样,针对拉萨裸裂尻鱼(Schizopygopsis younghusbandi younghusbandi)设计Cytb基因的特异性引物和探针,利用微滴式数字PCR(ddPCR)检测水样中e DNA拷贝数,并分析其与生物量和丰度之间的相关性。结果显示,正反向引物及探针序列与其他19种鱼之间的平均错配碱基数分别为6.8、6.9和3.6,且对其基因组DNA进行ddPCR扩增没有荧光信号。通过对比ddPCR和网捕2种方法,70%样点中检测结果相同,剩余30%样点都是网捕未捕获但ddPCR检出的情况。在拉鲁湿地和雅鲁藏布江干流的样点中,水样eDNA拷贝数与拉萨裸裂尻鱼生物量和丰度之间均具有显著的相关性,拉鲁湿地水样e DNA与二者的相关系数分别为0.987和0.647,雅鲁藏布江水样eDNA与二者的相关系数分别为0.786和0.756,表明eDNA技术是鱼类分布和生物量监测的有效方法。eDNA检测易受到近缘物种和水体理化性质的影响。

去氢骆驼蓬碱治疗细粒棘球蚴病的作用机制研究

目的 应用网络药理学方法预测去氢骆驼蓬碱(HM)治疗细粒棘球蚴病的作用机制。方法 从中药系统药理学数据库(TCMSP)、瑞士靶点预测数据库(SwissTargetPrediction)、药物银行数据库(Drugbank)获取HM相关基因,在基因卡数据库(GeneCards)、DISGENET数据库、DrugBank数据库获取细粒棘球蚴病的作用靶点,将HM的预测靶点和细粒棘球蚴病相关基因相互映射,得到HM作用细粒棘球蚴病的靶点基因,导入String数据库进行网络拓扑属性分析,筛选重要靶点蛋白,构建蛋白质-蛋白质互作(PPI)和成分-疾病-靶点网络。采用DAVID数据库进行基因本体论(GO)功能分析和Kyoto京都基因与基因组百科全书(KEGG)通路富集分析,筛选与DNA损伤相关的基因靶点。采用Autodock Vina软件及Pymol软件对相关靶点进行分子对接验证和展示。将活力不低于98%的细粒棘球蚴随机分为空白对照组、1%DMSO组、25μmol/L HM组、50μmol/L HM组、100μmol/L HM组,采用实时荧光定量逆转录聚合酶链式反应(qRTPCR)法、免疫印迹(Western blot)法体外验证HM干预细粒棘球蚴肿瘤蛋白P53(TP53)、拓扑异构酶Ⅰ(TopoⅠ)、染色体组蛋白H2A的变异体(H2AX)、共济失调毛细血管扩张突变基因(ATM)mRNA和蛋白表达水平。结果 共获得HM靶点105个,细粒棘球蚴病相关基因88个,二者共有靶点为2个。HM干预细粒棘球蚴病的作用靶点主要有促分裂原活化蛋白激酶3(MAPK3)、MAPK1、TP53、热休克蛋白90α家族A类成员1(HSPAA1)、MAPK14、Jun,机制可能涉及MAPK信号通路、受体酪氨酸激酶(ERBB)信号通路、DNA损伤与DNA修复通路、细胞凋亡等过程。体外验证结果显示,与空白对照组相比,25μmol/L HM组、50μmol/L HM组、100μmol/L HM组的TP53,TopoⅠmRNA和蛋白表达均呈下调趋势(P <0.05),H2AX,ATM mRNA和蛋白表达均呈上调趋势(P <0.05)。结论 HM可通过多种生物学过程和相关信号途径治疗细粒棘球蚴病,HM参与细粒棘球蚴病DNA损伤与DNA修复信号通路的调控作用,TP53,TopoⅠ,H2AX,ATM均可能是其作用靶点。该研究为进一步阐明HM治疗细粒棘球蚴病的分子机制奠定了基础。

淡水鱼类环境DNA宏条形码引物的筛选及其在千岛湖的应用

基于环境DNA(eDNA)技术的鱼类多样性监测方法因具有灵敏度高、对目标生物无伤害以及成本低等特点,近年来在国内外得到了广泛应用。eDNA方法的有效性往往取决于宏条形码引物的选择,尽管目前已经有一些鱼类环境DNA宏条形码引物,但较少有研究综合评估这些引物的检出效果。本研究评估了来自COI、Cytb、12S rRNA和16S rRNA基因的29对鱼类e DNA宏条形码引物(包括本研究设计的2对和从国内外文献中引用的27对引物),首先基于计算机模拟PCR(in silico PCR)进行了初步分析,随后通过高通量测序对其中效果较好的17对引物开展了更进一步的验证,结果显示:计算机模拟PCR结果良好的引物在进行高通量测序时并非全部表现良好,表明引物的筛选不能仅仅依靠计算机模拟PCR;具有更长扩增片段长度的宏条形码引物并没有获得理想中更好的扩增效果,表现效果好的引物大多是扩增片段长度处于200~300 bp之间的引物;相对于COI和Cytb而言,12S rRNA引物与16S rRNA引物均具有良好的扩增效果,适宜作为鱼类环境DNA宏条形码而用于鱼类多样性研究;同时,鉴于当前的鱼类DNA条形码数据库尚不完备以及不同引物的特性不同,使用多对引物将大大增加物种的检出概率和e DNA研究的可信性。本研究展示了eDNA在评估生物多样性方面的潜力,有助于将来的鱼类eDNA研究,从而为鱼类多样性的保护提供参考。

3种褐黄血蜱基因组DNA提取方法的比较

目的在保持褐黄血蜱Haemaphysalis flava寄生蜱虫体形态完整的前提下,综合比较95℃水浴法、改良碱裂解法、离心柱法3种提取方法对蜱组织DNA提取质量的差异,筛选适用于蜱鉴定分型的高效稳定基因组DNA提取方法。方法取蜱标本的一只足作为实验样本,通过95℃水浴法、改良碱裂解法和离心柱法分别提取样品中基因组DNA,检测提取物浓度以及A260/A280和A260/A230比值,并通过PCR技术检测蜱分型相关基因16S rDNA(16S ribosoma DNA,16S核糖DNA)、ITS2(internal transcribed spacer 2,内转录间隔区2)的片段扩增效率,综合分析3种提取方法的优劣。多组之间使用单因素方差分析(ANOVA检验),两组之间比较采用t检验分析。P<0.05为差异有统计学意义。结果3种提取方法均可获得足量的蜱基因组DNA,改良碱裂解法提取效率显著高于其他2种方法(P<0.05),A260/A280和A260/A230比值结果表明离心柱提取法获得的DNA纯度更高,进一步的PCR实验表明,在模板量一致的情况下,以离心柱法提取的DNA为模板扩增产生的16S rDNA、ITS2片段扩增效率更高,而以95℃水浴法提取的DNA为模板扩增产生的16S rDNA、ITS2片段效率较低。结论离心柱法是提取蜱基因组DNA高效且实用的方法,能够在保持虫体形态完整的情况下满足对寄生蜱进行后续基因分型实验的要求。

DNA甲基化修饰对金钱鱼卵巢Cyp17a1表达水平的影响

【目的】分析DNA甲基化修饰对金钱鱼(Scatophagus argus)卵巢Cyp17a1表达的影响,进一步认识卵巢发育成熟相关基因表达的调控机制。【方法】分别取卵巢发育III、IV期的金钱鱼,以及投喂添加0(对照)、50、100μg/g雌二醇饲料30 d的2龄雌鱼,用MethPrimer软件分析其Cyp17a1基因CpG二核苷酸位点分布特征,并预测CpG岛;采用亚硫酸氢盐测序法检测不同发育时期卵巢以及投喂雌二醇个体卵巢中的Cyp17a1的DNA甲基化修饰水平,并用实时荧光定量PCR分析Cyp17a1基因表达水平。【结果】金钱鱼Cyp17a1翻译起始位点2000 bp后无CpG岛,取第1外显子含有5个CpG位点(翻译起始位点后106、116、129、148和203 bp处)的区域用于DNA甲基化水平检测。金钱鱼III期卵巢Cyp17a1外显子1的DNA甲基化修饰水平显著高于IV期卵巢(P<0.05),与其mRNA表达水平呈负相关。116、129和203 bp处DNA甲基化存在发育时期差异,但106和148 bp处差异不显著(P>0.05)。投喂雌二醇后,金钱鱼卵巢Cyp17a1 mRNA表达水平和第1外显子CpG富集区域整体DNA甲基化修饰水平无显著变化(P>0.05),但雌激素处理雌鱼翻译起始位点后148、203 bp处甲基化水平明显上升(P<0.05)。【结论】金钱鱼卵巢Cyp17a1第一个外显子CpG富集区的整体甲基化水平与基因表达呈负相关,饲料E2可上调Cyp17a1第一个外显子148、205 bp处甲基化水平,表明甲基化修饰参与金钱鱼Cyp17a1的表达调控。

生产加工过程食用玉米淀粉基因降解情况

含有转基因成分的玉米在生产加工过程中核酸成分受到不同程度破坏,增加出口过程中转基因成分检验难度。针对转基因食用玉米淀粉在加工过程中主要环节进行样本收集,使用荧光定量聚合酶链式反应(polymerase chain reaction,PCR)对加工过程中样品内、外源基因不同扩增片段进行定量研究。研究发现,浸泡后的浆料湿磨及精磨分离阶段的样品DNA降解严重。随着检测转基因成分方法的不断创新和提高及数字PCR在检测领域的开发和应用,利用数字PCR方法检验痕量转基因成分,不仅可以定性检测,并且可以对转基因成分含量进行定量检测。

Case Study for Undetermined Mosquito Species by Polymerase Chain Reaction in Western Burkina Faso

Introduction: Malaria eradication campaigns all over the world are largely based on parasite and vector control. Vector identification, whether morphological or molecular, is an essential component of vector control. This study analyzed the possible causes of indeterminate polymerase chain reaction (PCR) results for mosquito species in Western part of Burkina Faso. Methodology: From July 2021 to November 2021, mosquitoes were collected during the period of high malaria transmission in the village of Séguéré, Houet province, Burkina Faso, and morphologically identified. After DNA extraction, samples were amplified by sine 200× PCR to identify species of the Anopheles gambiae complex. Indeterminate samples were then selected for further analysis. The parameters studied were: DNA dilution, the effect of protocol adjusting, and the type of protocol used. Results: A total of 130 “indeterminate” DNAs diluted 1:10 were analyzed. After dilution, the mean amount was 14.73 ± 3.59 ng/μL and absorbance 1.71 ± 0.1. PCR chain reaction yielded 94.62% (123/130) anopheline species in SINE PCR, 5.38% (7/130) “negative”. A significant difference between SINE PCR before dilution and after dilution was observed (P < 0.001). Identification tests carried out using other protocols gave no positive results. From these results, we note that the adaptation of the protocol significantly reduced the polymerase amplification results of the species. Conclusion: It is therefore necessary to respect the amplification protocols. However, the persistence of “indeterminate” results suggests that further studies should be carried out to shed more light on the subject.

单粒蔬菜种子DNA快速提取方法的建立

利用磁珠法对甘蓝、白菜、芥菜、洋葱、黄瓜、番茄、辣椒等7种形状、大小不同的蔬菜单粒种子和幼苗进行DNA提取,采用内参基因Actin进行实时荧光定量PCR评价DNA质量,利用KASP(kompetitive allele specific PCR)标记检验DNA质量是否达到KASP检测要求。结果显示,单粒种子磁珠法提取的各蔬菜DNA平均Ct值均处于19~24范围内。KASP检测进一步证实种子提取DNA的质量达到KASP标记分型的要求。综上所述,本研究建立了一种简单、经济、实用性强的单粒种子DNA提取方法,该方法对不同大小的蔬菜种子具有较好的稳定性,且大幅缩短了获得基因型数据的时间。

Evolution of Mother-to-Child HIV-1 Transmission Rate in Mali from 2009 to 2018

Despite enormous efforts to achieve the goal of eliminating mother-to-child transmission of HIV-1, it remains a major challenge for many countries in sub-Saharan Africa, particularly Mali. Our objective is to assess changes in the rate of mother-to-child transmission of HIV-1. We conducted a cross-sectional study between January 1, 2009 to December 31, 2018 (10 years) of early diagnosis activity in newborns and children born to HIV-1-positive mothers at the National Institute for Public Health (INSP). The samples came from health and referral centers in mali. All samples were received at the Laboratory of Molecular Biology at the INSP. Proviral DNA extraction was performed from a blood spot sample with a Roche DNA kit, Cobas AmpliPrep/Cobas TaqMan HIV-1 qualitative Test, V2.0 (Roche Molecular System, Inc, USA) following the company procedures. Molecular diagnosis was performed using the same kits using an algorithm of three identical PCRs. The Epi Info version 7 software was used for data analysis with a significance threshold of 5%. A total of 10,714 samples of infants and children born to HIV-positive mothers were analyzed by PCR. Ninety-six percent of mothers were on ARV prophylaxis (AZT 3TC NVP and AZT NVP) and 60% of newborns received the same ARV prophylaxis. Of these children, 956 tested positive with an overall transmission rate of 8.92%, varying between 7.27% in 2009 and 08.01% in 2018. This rate was relatively low among children receiving prophylaxis at 2.04% and remained high for children who received breastfeeding at 5.62%. However, the transmission rate remains low for those who have benefited from mixed and artificial breastfeeding at 1.58% and 1.27% respectively. A significant proportion of children remained infected by their mothers during pregnancy, childbirth or breastfeeding. This study shows the importance of early diagnosis of HIV in children using molecular technology.

深入了解目的基因(Bt基因)的检测与鉴定

目的基因的检测与鉴定是基因工程基本操作程序的最后一步,用以确定目的基因是否真正在受体细胞中稳定表达其遗传特性。本文结合实际教学案例,介绍目的基因的检测和鉴定方法,为理解基因工程提供一定的参考。

LRRTM1基因甲基化是胰腺癌的潜在诊断和预后标志物

目的探讨LRRTM1基因在胰腺癌中的表观遗传调控机制及其甲基化作为诊断和预后标志物的可能性。方法应用半定量RT-PCR与甲基化特异性PCR(methylation-specific PCR,MSP)技术检测6株胰腺癌细胞系中LRRTM1的表达及启动子区甲基化情况,应用MSP在101例癌前病变样本和277例胰腺癌组织中检测LRRTM1启动子区甲基化情况,并分析LRRTM1甲基化与临床病理因素之间及胰腺癌患者总生存期的关系。结果LRRTM1在Capan1、Panc3.11、AsPC1和PANC-28细胞中缺失表达,其MSP结果为完全甲基化状态,在Capan2和CFpac1中正常表达,MSP结果为未甲基化状态。应用去甲基化药物5-aza-dc处理细胞后,LRRTM1在Capan1、Panc3.11、AsPC1和PANC-28细胞恢复表达,在Capan2和CFpac1细胞中表达未改变。表明LRRTM1基因在胰腺癌中的表达受甲基化调控。在16.83%(17/101)的癌前病变样本和52.35%(145/277)的原发性胰腺癌中,LRRTM1发生甲基化,且LRRTM1甲基化与患者的年龄相关(P<0.05)。在获得随访信息的232例胰腺癌组织样本中发现LRRTM1甲基化与胰腺癌患者总生存期呈负相关。结论LRRTM1基因在胰腺癌组织中频繁发生甲基化,其表达受启动子区甲基化调控,LRRTM1甲基化是胰腺癌潜在的诊断和预后标志物。

大肠埃希菌DNA质控品的研制

研制大肠埃希菌DNA残留量测定所用质控品。抽提大肠埃希菌基因组DNA作为质控品原料,通过紫外分光光度法和电泳进行纯度和含量测定,采用紫外分光光度法和定量PCR法检测其均匀性和稳定性,并评价其加标回收率。经检测,A_(260)/A_(280)均在1.8~2.0之间,电泳图谱条带单一,无RNA和寡核苷酸存在。应用紫外分光光度法和定量PCR法对质控品进行均匀性和稳定性检测,统计结果表明,质控品均匀性良好;在-20℃的保存条件下,半年内未发现不稳定现象;在25℃的保存条件下,7 d内未发现不稳定现象。进行定量PCR法测定,在10^(-2)~10^(3)pg之间线性良好,标准曲线R值为0.997,斜率为-3.65,同时每组加标样品的回收率在70%~130%之间,S_(RSD)≤20%。该批大肠杆菌DNA质控品各项指标均符合要求,可作为质控品用于定量PCR检测大肠埃希菌的DNA残留量,含量定为111.73μg/mL。