1.Whyheat inactivated serum? Is it necessary to do heat inactivation?
56 ℃ heating can inactivate thecomplement system. Activated complement is involved in lysing cellular events,stimulating smooth muscle contraction, releasing histamine from cells andplatelets, and activating lymphocytes and macrophages. In immunologicalstudies, ES cell culture, insect cells and smooth muscle cells,heat-inactivated serum is recommended.
Experimentshave shown that heat-inactivated serum, correctly processed, is not requiredfor most cells. The treated sera had little or no effect on the growth of thecells and often resulted in a decrease in the rate of cell growth even thoughthe quality of the sera was usually affected by the high-temperature treatment.The heat-treated serum, the formation of sediment will be significantlyincreased, the deposit observed under an inverted microscope like "blackspots", often make researchers mistaken for serum contamination, and theserum on the 37 ℃ In the environment, thissediment will be more and more, so that the researchers mistakenly believe thatthe division of microbial expansion.
2.How tothaw serum will not make the product quality damage?
Whenthawing serum, follow the recommended gradual thawing method (-20 ° C to 4 ° Cto room temperature). If the temperature of thawing is too high (e.g., -20 ° Cto 37 ° C) when thawing, experiments show that sedimentation is very likely tooccur. Thaw serum, please shake it at any time, so that the temperature andcomposition uniformity, reduce the occurrence of precipitation. Do not put theplasma at 37 ℃ for too long, if left at 37 ℃ for too long, the serum willbecome cloudy, while many of the more unstable components of serum will,therefore, be compromised, and affect the quality of the serum. Serum heatinactivation is very likely to cause increased sediment, if not necessary; youcan do this step without having to do. If you must do the heat inactivation ofserum, please follow the principle of 56 ℃, 30 minutes, and shake evenly atany time. Temperature is too high, too long or uneven shaking, will causeincreased sediment.
3.serumthawed flocculent precipitate appeared, how to deal with?
Precipitationin serum occurs for a number of reasons, but the most common cause is due tothe denaturation of lipoproteins in the serum, and fibrin, one of the proteinsthat form the blood clot, is also present in the serum after thawing of theserum, Is also one of the main causes of sediment. However, these flocculentsediments do not affect the quality of the plasma itself. If you want to removethis flocculent sediment, the serum can be aliquoted into sterile centrifugetubes and centrifuged at 400g. The supernatant can then be filtered into themedium. We do not recommend that you filter out these flocculent sedimentsbecause it may clog your filter membrane.
4 What isthe best way to save your serum?
Therecommended serum should be stored at -5 ° C to -20 ° C. If stored at four ℃, please do not exceed one month.If you can not run out of a bottle, it is advisable to sterilize the aliquotsto sterile centrifuge tubes and return to freezing.
prev:Chip experiment is not satisfactory, click here！(2018-01-22)
next:Passage Time - How to arrange mammaliancells and insect cells?(2018-01-23)