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OBJECTIVES@#To examine the effect of improving diatom DNA extraction by glass bead - vortex oscillation method.@*METHODS@#The DNeasy PowerSoil Pro kit was used as control, two plant DNA extraction kits with different principles (New Plant genomic DNA extraction kit and Plant DNA Isolation kit) and one whole blood DNA extraction kit (whole blood genomic DNA extraction kit) were selected to extract diatom DNA from lung tissue and water sample of the same drowning case. The combination of mass ratio of glass beads with different sizes and vortex oscillation time was designed, and the optimal DNA extraction conditions were selected with the addition of glass beads oscillation. The extracted products of the conventional group and the modified group were directly electrophoretic and detected by diatom specific PCR. Finally, all the extracts were quantified by qPCR, and the Ct values of different groups were statistically analyzed.@*RESULTS@#When the frequency of vortex oscillation was 3 000 r/min, the optimal combination of DNA extraction was vortex oscillation for 4 min, and the mass ratio of large glass beads to small glass beads was 1∶1. The DNeasy PowerSoil Pro kit was used as a reference, and the Ct value of 10 mL water sample was greater than that of 0.5 g tissue. The Ct values of the other three kits used for plant DNA extraction decreased after the glass beads-vortex oscillation method was used, and the Ct values of the tissues before and after the improvement were statistically significant (P<0.05). The whole blood genomic DNA extraction kit used in this study could successfully extract diatom DNA, the extraction of water samples was close to DNeasy PowerSoil Pro kit, after the modified method was applied to tissue samples, the difference in Ct value was statistically significant (P<0.05). However, when the three kits were used to extract diatom DNA from water samples, Ct values before and after the improvement were only statistically significant in New Plant genomic DNA extraction kit group (P<0.05).@*CONCLUSIONS@#The improved glass bead-vortex oscillation method can improve the extraction efficiency of diatom DNA from forensic materials, especially from tissue samples, by plant and blood DNA extraction kits.
Subject(s)
DNA, Plant/genetics , Diatoms/genetics , Real-Time Polymerase Chain Reaction , WaterABSTRACT
BACKGROUND: Increasing attention has been paid to vascular components of the adipose-derived matrix and adipose-derived stem cells in tissue engineering. Existing methods for separating the vascular components of the adipose-derived matrix mainly include enzymatic and bolus injection, both of which have fatal disadvantages. OBJECTIVE: To search for a method for preparing adipose-derived stromal vascular fractions with high efficiency, safety, and simplicity. METHODS: The group without any treatment was used as the negative control, and the enzymatic hydrolysis method served as the positive control. The enzymatic hydrolysis method, traditional bolus method, modified bolus method, glass beads method and built-in ultrasonic waves method were compared through cell volume, survival rate, cell fragments, cell viability, increment rate and detection of microbial infection. The enzymatic hydrolysis method and the common bolus injection method were commonly used in the separation of vascular component cells of the fat source matrix; the improved bolus method was a method obtained by improving on the basis of the ordinary bolus method; the glass bead method was to use the glass bead to oscillate. The shear force generated was obtained by adding glass beads to the fat granules and shaking at 2 500 r/min for 9 minutes to prepare stromal vascular fraction cells. Using the built-in ultrasonic method, adipose tissue was treated at 25 W for 36 seconds to obtain stromal vascular fraction cells through a cavitation effect. RESULTS AND CONCLUSION: (1) The size of stromal vascular fraction cells isolated by five methods showed no significant difference (P > 0.05). (2)The cell viability was lowest in the negative control group, and highest in the enzymatic hydrolysis group. The cell viability in the enzymatic hydrolysis, glass bead, and built-in ultrasonic wave groups was significantly higher than that in the modified and traditional bolus groups (P < 0.05). (3) The cell survival rate and cell proliferation rate in the enzymatic hydrolysis, glass bead, and built-in ultrasonic wave groups were significantly higher than those in the modified and traditional bolus groups (P < 0.05). (4) The cell fragmentation rate and cell apoptosis rate in the enzymatic hydrolysis, glass bead, and built-in ultrasonic wave groups were significantly lower than those in the modified and traditional bolus groups (P < 0.05). (5) These results indicate that the built-in ultrasonic method and the glass bead method are better in enriching vascular components of the adipose-derived matrix. But glass bead method adds exogenous products, so it increases the risk of pollution. Built-in ultrasonic method inserts the ultrasound probe into the adipose tissue, but as long as the ultrasound probe is thoroughly sterilized, the risk of contamination is minimized. In general, the built-in ultrasonic method and the glass bead method are superior to modified and traditional bolus methods.
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Objective To establish a reliable approach for quantification of colony forming unit(CFU)of Mycobac-terium tuberculosis (M.tb)by measuring optical density(OD).Methods M.tb suspension H37Ra was prepared using low-power ultrasonic or glass bead beating methods,and was two-fold serially diluted,OD at 600nm (OD600)of each dilution ratio was measured respectively,OD600 and dilution curve were analyzed to determine the optimum approach for preparing bacterial suspension,linear range of OD600,as well as linear relationship between OD600 and CFU.Results OD600 was 0.1 -0.6,linear regression analysis of OD600 and dilution ratio within linear range revealed that correlation coefficient (R2 )of glass bead beating and low-power ultrasonic methods were 0.98 and 1 .00 respectively,both presented a good correlation,low-power ultrasonic method was better than glass bead beat-ing method,bacterial suspension dispersed more evenly.Linear regression analysis results of OD600 and CFU val-ues showed that the regression equation of glass bead beating method and low-power ultrasonic method were CFU=2.35×107 ×OD600+4.42×105 and CFU=3.26×107 ×OD600+6.89×105 respectively.Conclusion Low-power ultrasonic method is a good method for preparation of M.tb suspension,combined the measurement of OD600 value, it can be a reliable and rapid method for quantitative analysis of M.tb.
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The oocyst wall is severed by means of mechanical injury or chemical agents. This study reports the percentage of in vitro sporocyst release following mechanical shaking in the presence of varying sizes of glass beads. Glass beads measured 0.5, 1, and 3 mm in diameter and were shaken with the oocysts for different times ranging from 5 sec to 5 min. Approximately 80% of sporocysts were released with 5 min of shaking in the presence of 3 mm glass beads, as well as 30 sec with 0.5 mm beads and 1 mm glass beads. The release of sporocysts of E. tenella was most efficient using 1 mm glass beads and treatment times of 30 sec to 1 min. Therefore, the use of 1 mm glass beads with 30 sec to 1 min of agitation is recommended in order to maximize sporocyst release and recovery and to improve the yield of viable sporozoites for use in biochemical, tissue culture, and immunological applications of coccidia.
Subject(s)
Eimeria tenella/physiology , Glass , Mechanical Phenomena , Microspheres , Oocysts/physiology , Parasitology/methods , Stress, Physiological , Time FactorsABSTRACT
A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved.