共查询到20条相似文献,搜索用时 15 毫秒
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K. R. May 《Applied microbiology》1969,18(3):513-514
The useful life of agar in aerosol samplers is greatly extended by treatment with a dilute emulsion of oxyethylene docosanol. Growth of viable organisms is unaffected. 相似文献
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Morphogenetic processes often occur in fungal cultures in agar medium. These processes are difficult to study by light microscopy because the hyphae or other structures fail to have sufficient contrast for detailed study and photography. To overcome this difficulty, we developed a method to stain hyphae inside the agar without affecting the medium itself. 相似文献
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A new procedure of assaying interferon (IF) has been developed. Cell suspension was dispensed into liquid scintillation counting vials together with IF sample. During an overnight incubation, the cells adhered sufficiently to the bottom of the vials and all the subsequent procedures were carried out without transfer of the cells from the vials. Vesicular stomatitis virus was inoculated and virus-specific RNA was labeled by adding 3H-uridine and actinomycin D to the medium. Incubation was terminated prior to completion of a single-step growth of the virus and radioactivity of the labeled cells in each vial was determined. The reciprocal of the IF dilution which reduced the radioactivity in viral RNA by 50% was taken as the titer. The present procedure consists of simple manipulations and can be completed within 24 hr. Furthermore, it is quite reproducible and gives a titer almost identical to that obtained by the conventional plaque-reduction dose method. The procedure can be applied to mouse L cells, rabbit RK-13 cells and human FL cells, without modification. 相似文献
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A Simple and Rapid Method for Genetic Transformation of Lactic Streptococci by Electroporation 总被引:26,自引:19,他引:26
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Ian B. Powell Marc G. Achen Alan J. Hillier Barrie E. Davidson 《Applied microbiology》1988,54(3):655-660
An electroporation procedure for the plasmid-mediated genetic transformation of intact cells of Streptococcus cremoris and Streptococcus lactis was performed. Ten different strains were transformed. The method was simple and rapid and yielded transformant colonies in 14 to 24 h. The method was optimized for S. lactis LM0230, and transformation frequencies of between 1 × 104 and 5 × 105 transformants per μg of purified plasmid (pMU1328) were achieved routinely. The optimized procedure involved lysozyme treatment of cells. Transformation of LM0230 occurred at comparable frequencies with pLS1 (4.4 kilobase pair [kbp]), pMU1328 (7.4 kbp), and pAMβ1 (26.5 kbp). Plasmid DNA isolated from transformants had not undergone detectable deletions or rearrangements. Transformation was possible with plasmid DNA which was religated after restriction endonuclease digestion. Phage DNA-dependent transfection of S. lactis LM0230 and S. lactis C6 was also achieved. 相似文献
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血液基因组DNA的快速提取方法 总被引:4,自引:0,他引:4
目的:研究血液中基因组DNA的简便快速提取方法。方法:取新鲜抗凝血,以红细胞裂解液除去红细胞,再破碎白细胞,除去杂蛋白,获得基因组DNA。结果:所得基因组DNA完整、无断裂,含量和纯度均较高。以所提基因组DNA作为模板能很好的扩增出p21因子启动子序列,因此该法所提取的DNA是完整可靠的。结论:该法能简便、快速、安全、廉价的提取血液中的基因组DNA,并适用于临床检测和分子生物学研究。 相似文献
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G. M. Tallis 《Biometrical journal. Biometrische Zeitschrift》1982,24(7):663-672
The concept of balanced sampling is applied to prediction in finite samples using model based inference procedures. Necessary and sufficient conditions are derived for a general linear model with arbitrary covariance structure to yield the expansion estimator as the best linear unbiased predictor for the mean. The analysis is extended to produce a robust estimator for the mean squared error under balanced sampling and the results are discussed in the context of statistical genetics where appropriate sampling produces simple efficient and robust genetic predictors free from unnecessary genetic assumptions. 相似文献
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基于双链DNA结合染料能特异嵌入双链DNA发出荧光的原理,发展了一种实时检测DNA聚合酶活性的简便方法.在检测过程中,聚合酶的聚合反应进程被实时转换为荧光信号,通过监测荧光强度的变化实时检测聚合酶的活性及药物对聚合酶活性的影响.该方法不需要对DNA进行放射性同位素标记和荧光标记,也不需要聚丙烯酰胺凝胶电泳和聚合酶链式反应,是一种简便、快速的聚合酶活性实时检测新方法,为研究抗肿瘤药物对聚合酶活性的影响提供了一种简捷方法,也将为相关疾病诊治和药物筛选提供一种新的思路. 相似文献
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Hans-Peter Grossart Grieg F. Steward Josefina Martinez Farooq Azam 《Applied microbiology》2000,66(8):3632-3636
We developed a simple, rapid method for demonstrating flagellation of bacteria using the fluorescent protein stain NanoOrange (Molecular Probes, Eugene, Oreg.). The NanoOrange reagent binds to hydrophobic regions of proteins, which results in substantial enhancement of fluorescence. Unbound reagent is essentially nonfluorescent. NanoOrange fluorescently stained bacterial cell bodies, as well as flagella and other appendages, which could be directly observed by epifluorescence microscopy. Detection of flagella was further improved by using a charge-coupled device camera for image capture and processing. The reliability of the method was tested by using 37 pure cultures of marine bacteria. Detection of flagella on the isolates by NanoOrange staining was compared to detection by transmission electron microscopy (TEM). For 36 of 37 cultures, the two methods yielded the same results. In one case, flagella were detected by TEM but not by NanoOrange, although the difference may be attributable to differences between the culture preparations. NanoOrange staining is rapid (10 to 15 min) and does not require fixation or dehydration, so live samples can be stained. Since NanoOrange is a general protein stain and works directly in seawater, it may also prove to be useful for staining other proteinaceous material that is of interest to aquatic microbial ecologists. 相似文献
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Rand R. Wilcox 《Biometrical journal. Biometrische Zeitschrift》1996,38(2):173-180
A well known result is that skewness can cause problems when testing hypotheses about measures of location, particulary when a one-sided test is of interest. Wilcox (1994) reports both theoretical and simulation results showing that when testing hypotheses about trimmed means, control over Type I error probabilities can be substantially better than methods for means. However, at least in some situations, control over the probability of a Type I error might still be judged to be inadequate. One way of adressing this concern is to combine trimmed means with the bootsrap method advocated by Westfall and Yuong (1993). This note reports simulation results indicating that there are situations where substantial improvements over Type I error probabilities are indeed obtained. 相似文献
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B. V. S. Sisodia 《Biometrical journal. Biometrische Zeitschrift》1985,27(1):97-100
In this note, an attempt has been made to study the effect on MVLUE of a population mean on the second occasion in successive sampling when sample values of correlation and regression coefficients are used in it. It was found that increase in the MSE of derived biased estimator is of the order q2ρ2 which may be negligible till the proportion of unmatched units (q) and correlation coefficient (ρ) are quite small. 相似文献
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J. E. R. Staddon Lee W. McGeorge R. A. Bruce F. F. Klein 《Ethology : formerly Zeitschrift fur Tierpsychologie》1978,48(3):306-330
A simple, real-time method for displaying the information contained in the zero-crossings of acoustic signals is described. The method can be used even with many signals that have harmonics, and reveals a wealth of fine structure in bird song. Some of this structure may serve a communicatory function. 相似文献
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A. P. WALKER 《Journal of applied microbiology》1981,51(3):405-408
A strain of Pseudomonas aeruginosa having colonies that resemble those of salmonellas on brilliant green agar is almost totally inhibited by the addition of 1.0 mg/ml of sulphacetamide to the medium. Low numbers of Ps. aeruginosa grew equally well on brilliant green and nutrient agar, but 106 –107 organisms were needed before any growth appeared on the medium containing sulphacetamide. During 12 months of routine use of the sulphacetamide medium, involving almost 3000 plates, Ps. aeruginosa has been isolated as a contaminant only once. Forty-seven salmonella serotypes were grown on the sulphacetamide brilliant green agar in the same period. 相似文献
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通过基因突变方法制备的单体速效胰岛素Lispro Insulin已上市用于治疗糖尿病,如何利用简便快速的方法研究获得新的单体速效胰岛素成为研究的热点。以Lispro Insulin为模型,利用猪胰岛素的胰蛋白酶酶切大片段(DOI,去B链C端八肽胰岛素)和化学合成的八肽,通过胰蛋白酶的酶促合成方法为筛选新的单体速效胰岛素提供了新的途径。结果显示,酶促合成得到的95%纯度的Lispro Insulin具备了单体速效胰岛素的不自身聚合的特点。 相似文献