Response surface methodology (RSM) has been used to optimize the extraction conditions of antioxidants with relatively low caffeine content from green tea by using ultrasonic extraction. The predicted optimal conditions for the highest antioxidant activity and minimum caffeine level were found at 19.7% ethanol, 26.4 min extraction time, and 24.0 ° C extraction temperature. In the predicted opti...

The mechanism of DNA degradation and its clinical applications were examined. When purified lambda phage and extracted liver DNA were fixed in phosphate buffered formaldehyde, the DNA did not degrade, but there was incomplete digestion with endonuclease. Rat liver tissues were fixed under various conditions and DNA extracted. Immediate fixation with buffered formaldehyde at low temperature, or ...

According to the unique properties and many applications of nano gold powder, it was prepared from an acid leaching tail solution. The low value residual gold ions existed in acid leaching tail solution in Mouteh gold mine in Iran with fellow heavy metals as pollutants (Fe2+, Cu2+, and Zn2+). Preparation of nano gold particles is achieved by two steps: First, by addition of ammonia as separatio...

According to the unique properties and many applications of nano gold powder, it was prepared from an acid leaching tail solution. The low value residual gold ions existed in acid leaching tail solution in Mouteh gold mine in Iran with fellow heavy metals as pollutants (Fe2+, Cu2+, and Zn2+). Preparation of nano gold particles is achieved by two steps: First, by addition of ammonia as separatio...

In the work described here, two techniques for the recovery of anthocyanins from potato peel were studied and compared. One of the techniques employed was supercritical fluid extraction (SFE) with pure CO2 or with CO2 and ethanol as cosolvent and the other technique was pressurized liquid extraction (PLE), where the solvent used was ethanol in water acidified to pH 2.6. The effects of pressure ...

MATERIALS Bacteriophage T4 DNA ligase T vector Target DNA (25 μg/ml), amplified by PCR When the PCR mixture contains more than one or two bands of amplified DNA, purify the target fragment by electrophoresis through low melting/gelling temperature agarose (please see Recovery of DNA from Low-meltingtemperature Agarose Gels: Organic Extraction). If not purified by gel electrophoresis, PCR-amplif...