ABSTRACT
Objective To optimize the experimental system of dual molecular beacon to rapidly detect My-cobacterium tuberculosis and its resistant strains.Methods Fluorescence quantitative PCR was carried out by selecting different magnesium ion concentration,annealing temperature and primer concentration respectively. Finally,the optimum reaction conditions were obtained.Results In order to ensure the efficiency of amplifica-tion and no non-specific amplification,the final selection of the best conditions were as follows,the concentra-tion of Mg2+was 3.0 mmol/L,annealing temperature was 60 ℃,and the concentration of primers was 0.3 mmol/L.Conclusion The optimal condition of dual molecular beacon experiment was established,which en-sured that the detection of Mycobacterium tuberculosis by molecular beacon quantitative PCR had the advanta-ges,such as simple operation,rapid speed,high sensitivity(the minimum detection limit was 1 CFU/mL)and specificity(only Mycobacterium tuberculosis complex including drug-resistant strains could be detected),good reproducibility(coefficient of variation was < 5%)and other advantages.The study provides the necessary conditions for the dual molecular beacon detection of Mycobacterium tuberculosis.
ABSTRACT
This project is targeted on exploring some improving approaches to isolate and culture the microorganisms which are difficult to be isolated and cultured through the conventional ways. The results showed that betaine, sodium pyruvate, SOD and catalase are helpful for increasing the total number and variety of isolated strains. A kind of combined method was also used to isolate the micro-colony which can not be seen by naked eyes on the plates. Totally 52 Actinomycetes and 103 bacteria and 17 fungi were obtained from 4 soil samples using the above methods. 4. 325% microorganisms were obtained as positive strains to inhibit the growth of some kinds of test bacteria, which is higher than the percent using generally isolated ones. These microbial natural products may remain an important resource for the drug discovery.
ABSTRACT
The effect of local hyperthermia of 41 to 43degree C for 30 minutes on radiosensitivity of normal tissue was studied utilizing jejunal crypt microcolony assay. Hyperthermia of this range enhanced the radiation effect and the effect was mainly additive without significant effect on the slopes of cell survival curves. At the isoeffect level of 20 microcolony formation, the thermal enhancement ratio was 1.02, 1.10 and 1.39 for 41degree 42degreeand 43degree C, respectively. The distribution of microcolony formation along the circumference of jejunum was not uniform, having more colonies around the mesenteric border, and this suggests the effect of uneven cooling by blood circulation.