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1.
A comparison was made of two methods for the extraction of enchytraeids, the O’Connor (1957) method and the Römbke (1995) method; the latter was originally proposed as a standard method for monitoring environmental pollution. The average number of enchytraeids extracted by the Römbke method was significantly greater. This simple and convenient method was shown to be as efficient as the traditional method when applied in both laboratory and field studies. 相似文献
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蚧虫基因组DNA不同提取方法的比较 总被引:5,自引:0,他引:5
实验以日本龟蜡蚧CeroplastesjaponicusGreen,白蜡绵粉蚧PhenacoccusfraxinusTang ,朝鲜球蚧DidesmococcuskoreanusBorchseniush和瘤大球坚蚧EulecaniumgiganteaShinji等 4种蚧虫为材料 ,分别用十二烷基硫酸钠 (SDS)法、十六烷基三乙基溴化铵 (CTAB)法、醋酸钾 (KAc)法和氯化钠 (NaCl)法等 4种方法 ,对单只蚧虫进行基因组DNA提取 ,用 0 8%琼脂糖凝胶电泳检测所提DNA。结果表明 ,4种方法都可以提取到基因组DNA ,但是比较而言 ,CTAB法和NaCl法所提取的DNA质量明显优于SDS法和KAc法 ,并适用于PCR。因此认为 ,CTAB法和NaCl法是实验室提取单只蚧虫基因组DNA更有效而实用的方法。 相似文献
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条斑紫菜丝状体总RNA提取方法比较 总被引:1,自引:0,他引:1
目的:为了获得质量较高的条斑紫菜丝状体总RNA,对几种常用提取方法进行研究。方法:以条斑紫菜自由丝状体为材料,比较了用异硫氰酸胍法、CTAB法、SDS/酚法、TRIzol法、RNAplant法提取的RNA的质量和纯度。结果:异硫氰酸胍法提取RNA的成本低,但纯度不高;CTAB法产率较小,且不能完全去除多糖或蛋白质;SDS/酚法未能获得完整的RNA;TRIzol法未能见到5SrRNA条带,且带有杂带;而RNAplant法提取RNA的质量好、纯度高、提取效率高,其D260nm/D280nm值为1.836,经逆转录得到的双链cDNA扩增产物长度在200bp以上。结论:实验结果表明RNAplant法更适于条斑紫菜丝状体总RNA的提取。 相似文献
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B Kriz V Burian K Sladky B Buriánová O Mottlová Z Roth 《Journal of hygiene, epidemiology, microbiology, and immunology》1978,22(4):485-493
In 33 human sera the determination of diphtheric antitoxic antibodies was performed in a double blind test using Jensen's method, the method of tissue cultures and the haemagglutination method. In the method of tissue cultures the antibody levels in the sera were determinated in the first and second experiment with the precision of +/- half dilution of the geometrical progression. In Jensen's method, the difference between the first and second measurements slightly exceeded +/- 1 dilution. In the haemagglutination method the error considerably exceeded the binary step dilution. In most cases, the determination fluctuated up to seven times the actual value. Differences among the mean values of examination results obtained by Jensen's method and the method of the tissue cultures are statistically insignificant. The differences between the haemagglutination method and both the other methods are statistically significant. 相似文献
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采用粗纤维法、凯氏定氮法、斐林试剂法、索氏浸提法、干灰化法和重量法等多种化学分析方法对云南翠雀花的化学成分进行了分析.结果显示,云南翠雀花含有丰富的维生素、矿质元素以及异亮氨酸、蛋氨酸、赖氨酸等17种氨基酸,其中粗纤维、VB2和蛋氨酸含量尤为丰富,分别为32.83%、3.26 mg·g-1、3.27 mg· g-1. 相似文献
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评价检测食品中大肠菌群不同方法。比较国家标准、行业标准和显色培养基检测方法检测大肠菌群结果的差别。国家标准和行业标准检测结果基本一致,但有差异,应用显色培养基检测大肠菌群优于目前使用的国家标准和出口食品检验行业标准方法。检测食品中大肠菌群,显色培养基检测方法快速、灵敏、特异。 相似文献
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鸢尾属药用植物总DNA提取方法的比较研究 总被引:3,自引:0,他引:3
以鸢尾属(Iris L.)药用植物鸢尾Iris tectorum Maxim.叶片为材料,分别采用CTAB法、高盐低pH法、SDS法和试剂盒法四种方法提取植物总DNA,并通过琼脂糖凝胶电泳、紫外分光光度计、ISSR和RAPD四种方法对所提取的DNA样品进行检测。结果表明,用SDS—I法提取的植物总DNA纯度、浓度和完整性都很高,从经济角度考虑优于用试剂盒提取,从提取效果考虑不亚于用CTAB法和高盐低pH法提取,是比较适合鸢尾属植物总DNA提取的方法。 相似文献
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Fujisawa H Eguchi S Ushijima M Miyata S Miki Y Muto T Matsuura M 《Bioinformatics (Oxford, England)》2004,20(5):718-726
MOTIVATION: Single nucleotide polymorphisms have been investigated as biological markers and the representative high-throughput genotyping method is a combination of the Invader assay and a statistical clustering method. A typical statistical clustering method is the k-means method, but it often fails because of the lack of flexibility. An alternative fast and reliable method is therefore desirable. RESULTS: This paper proposes a model-based clustering method using a normal mixture model and a well-conceived penalized likelihood. The proposed method can judge unclear genotypings to be re-examined and also work well even when the number of clusters is unknown. Some results are illustrated and then satisfactory genotypings are shown. Even when the conventional maximum likelihood method and the typical k-means clustering method failed, the proposed method succeeded. 相似文献
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改进的SDS-CTAB法提取濒危植物连香树总DNA 总被引:17,自引:0,他引:17
对珍稀濒危植物连香树(Cercidiphyllum japonicum)的6种总DNA提取方法进行了对比试验,结果表明改进的SDS-CTAB法更适合于连香树总DNA提取。该方法提取的DNA经紫外消光值检测,其A260/A280为1.8532,优于CTAB法(1.4872)、SDS法(1.3552)、PVP法(1.5079)、尿素法(1.1858)和高盐低pH法(1.4534)。琼脂糖凝胶电泳和PCR扩增结果也得出同样的结论。 相似文献
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酵母表达重组人血清白蛋白检测方法的比较 总被引:1,自引:1,他引:0
应用生化法、电泳扫描结合Bradford法、竞争ELISA等3种方法检测酵母表达重组人血清白蛋白(rHSA)的表达量。结果表明,3种方法检测结果近似。比较而言,生化法灵敏度较低,但操作简便,价格低廉;竞争ELISA法灵敏度最高,但需要特异的抗体;电泳扫描结合Bradford法需要特殊仪器,操作繁琐,花费时间长,灵敏度介于生化法和竞争ELISA法之间。综合利弊,生化法可作为检测酵母表达rHSA的首选方法,如条件允许,可考虑采用电泳扫描结合Bradford法或竞争EUSA。 相似文献
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A novel method was developed for the determination of the entrapped volume of liposomes. The obtained values of the entrapped volume by our "dilution method" agreed very well with those of the conventional "quenching method." The dilution method also offered the great advantages of simple procedure and high reproducibility. The principle and validity of our method are discussed. 相似文献
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Niemann H 《Theriogenology》1985,23(2):369-379
The effects of a one-step addition of 1.4 M glycerol (method A) upon morphological appearance and developmental capacity of frozen/thawed day 7 bovine embryos were investigated and compared to a standard stepwise addition of 1.0 M glycerol (method B). With method A, the percentage of intact embryos (classified as excellent, good and poor) was 95.3% (61 out of 64) without differences between morulae (96.5%) and blastocysts (94.4%). With method B, the percentage of intact embryos was 83.0% (44 out of 53). The percentage was similar for blastocysts (89.2%) and significantly (p < 0.05) lower for morulae (68.8%) when compared to method A. The percentage of embryos with a damaged zona pellucida was considerably increased with method A (26.6%) when compared to method B (13.2%). The proportion of embryos with excluded blastomeres was similar in both methods (21.9% method A, 17.0% method B). With method A, pregnancy rates after nonsurgical transfer were 51.0% (25 out of 49) and were better than with method B (40.5%; 15 out of 37). Embryos with a damaged zona pellucida resulted in a high pregnancy rate of 66.7% (8 out of 12). A pregnancy rate of 52.9% (10 out of 17) was obtained with embryos showing some excluded blastomeres. Thus, a one-step addition of 1.4 M glycerol facilitates and accelerates the process of embryo cryopreservation and is compatible with high pregnancy rates. Damage of the zona pellucida does not impair further development of frozen/thawed bovine embryos provided blastomeres are intact. 相似文献
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The Kato-Katz (KK) method is a well-known method of fecal examination for helminthiases. Its diagnostic sensitivity was found very high for clonorchiasis. The present study evaluated the correlation of Clonorchis sinensis egg counts by the KK method with those by direct smear and formalin-ether (FE) technique. The egg counts obtained by the KK method (Y) were correlated with the counts by direct smear (X) with the equation of Y = 659.4 + 0.266X (r2 = 0.738), but not with those by the FE method. The present study demonstrated that the KK method and direct smear were useful for both qualitative and quantitative diagnosis of clonorchiasis, especially in the field. 相似文献
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Coagulase-negative staphylococci (CNS) species identification is still difficult for most clinical laboratories. The scheme proposed by Kloos and Schleifer and modified by Bannerman is the reference method used for the identification of staphylococcal species and subspecies; however, this method is relatively laborious for routine use since it requires the utilization of a large number of biochemical tests. The objective of the present study was to compare four methods, i.e., the reference method, the API Staph system (bioMérieux) and two methods modified from the reference method in our laboratory (simplified method and disk method), in the identification of 100 CNS strains. Compared to the reference method, the simplified method and disk method correctly identified 100 and 99% of the CNS species, respectively, while this rate was 84% for the API Staph system. Inaccurate identification by the API Staph method was observed for Staphylococcus epidermidis (2.2%), S. hominis (25%), S. haemolyticus (37.5%), and S. warneri (47.1%). The simplified method using the simple identification scheme proposed in the present study was found to be efficient for all strains tested, with 100% sensitivity and specificity and proved to be available alternative for the identification of staphylococci, offering, higher reliability and lower cost than the currently available commercial systems. This method would be very useful in clinical microbiology laboratory, especially in places with limited resources. 相似文献
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采用正交试验设计,以桑黄菌丝体粗多糖含量为考察指标,用苯酚—硫酸法,分别确定了热水浸提法、微波辅助提取法和超声提取法的最佳工艺。通过极差分析得出:热水浸提法的最优工艺为浸提时间3 h、浸提3次、液料质量比50∶1、浸提温度90℃,粗多糖提取率为2.10%;微波提取法的最优工艺为微波处理15 min、液料质量比50∶1、提取3次,提取率为4.18%;超声提取法的最优工艺为超声30 min、提取2次、液料质量比60∶1、温度60℃、频率60 Hz,提取率为3.02%。微波辅助法与热水浸提法相比,时间缩短,且提取率提高近1倍;与超声提取法相比,时间缩短1/2,但提取率提高40%。因此,微波辅助提取法速度更快、提取效率更高、操作更简便,优于其他2种方法。 相似文献
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为了证实炭末明胶改良安瓿管法替代其他方法检测细菌是否产明胶酶,实验中采用营养明胶法、X线胶片法和炭末明胶改良安瓿管法对486株质控菌株、临床分离菌株进行明胶液化试验。结果显示,以营养明胶法培养的359株呈阳性反应,X线胶片法274株呈阳性反应,炭末明胶改良安瓿法423株呈阳性反应。营养明胶法明胶液化平均天数为3.3d,而炭末明胶改良安瓿法明胶液化平均天数仅为1.5d。炭末明胶改良安瓿法由于简单快捷,易于观察,而且试剂用量小、能够室温长期保存,该方法值得推广应用。 相似文献
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J. A. Donkersloot 《Antonie van Leeuwenhoek》1966,32(1):419-428
As a tool for the classification of yeasts a method is presented for determining the aerobic utilization of each of 28 carbon compounds distributed over 4 mixtures containing respectively 10, 7, 7 and 4 of these compounds. Paper chromatography is used to follow the eventual disappearance of each individual carbon compound from the medium. This method is compared to the well-known standard method where a growth response to singly offered compounds in liquid medium is used for biochemical characterization. The proposed method has two advantages: results are obtained more rapidly and with less work, and the paper-chromatographic method may reveal a time sequence of utilization. Both the new method and the established standard method were applied to eight yeasts. Although the backgrounds are different, the experimental results were similar. The method presented is suitable for the differentiation of species as well as of strains within one species. It should be considered for use in taxonomy. 相似文献