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BSA与BSA Fraction V
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| 麻烦请教下，牛血清白蛋白（BSA）和牛血清白蛋白第五组分（BSA Fraction V）是同一种蛋白吗？我查了BSA和BSA Fraction V的CAS号，都是9048-46-8。但还不是很肯定。哪位知道确切的答案不？呵呵。谢谢啦！ |
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blackdust(金币+2,VIP+0):非常感谢答疑。
blackdust(金币+2,VIP+0):非常感谢答疑。
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BSA fraction V 也是BSA，并不是BSA的一种组分，它其实是指一种特定提取方法得到的BSA，好像一般所用的都是这种。具体： Fact: Today, virtually no bovine albumin, and certainly none on a commercial scale, is produced using the full five fraction "Cohn" ethanol method, although albumin continues to go by the nickname "Fraction V". The often misunderstood terms "Fraction V" and "Cohn" as applied to albumin have their origins in the 1940s, when plasma fractionation was first invented. Human blood plasma was an important life-saving medical treatment, but also a highly perishable commodity that was often in short supply. A great need existed for material that could serve the life-saving functions of blood plasma but would be easier and more practical to store, inventory, transport and administer. Methods were sought to divide, or "fraction," the blood plasma into its active components to find stable substitutes for whole plasma. Dr. Edwin J. Cohn, a researcher at Harvard University, developed the true, original Cohn "fractionation" procedure in the 1940s. Dr. Cohn determined that different proteins in the blood could be separated from each other by using different temperatures and biochemical conditions and by the use of solvents like ethanol. His method used these biochemical techniques to separate the blood plasma into five fractions. The fifth fraction was albumin, the most abundant protein in the blood, which is why albumin is often referred to as "Fraction V." Albumin was an excellent substitute for human plasma. When administered to wounded soldiers or other patients with blood loss, it helped expand the volume of blood and led to speedier recovery. What's more, Cohn's method was gentle enough so the protein retained its biological activity. Recognizing the importance of this discovery, the government immediately stepped in and "asked" the major pharmaceutical companies of the time to commercialize Dr. Cohn's fractionation process. Later, there were many modifications and improvements to the method, and it was also applied to the production of animal albumin. Additional changes came about as researchers found new applications for bovine albumin in diagnostics, cell culture, microbial culture and biochemical research. Many of the new methods used heat, rather than solvents as the main fractionation technique. Others used acetone or salts like ammonium sulfate to separate the albumin from the other plasma components. One leftover of albumin history is that manufacturers may continue to refer to their method as "Cohn Fractionation," although the manufacturing process and the products bear little actual resemblance to the original. For many decades, the Cohn ethanol fractionated products have been widely accepted, but the reasons for performance have been little studied or understood, and the manufacturing processes have never been modernized. Proliant identified many areas for potential improvement. Compared to modern purification methods, Traditional Cohn fractionation is dangerous and environmentally unfriendly (ethanol is an organic solvent and a highly explosive, controlled substance), unsanitary (requires open tanks and filter presses that increase the possibility of contamination) and may be too gentle to kill certain kinds of viruses that require heat inactivation. Also, since there is no heating step, the BSA is often contaminated with immunoglobulins, which causes regulatory problems in pharmaceutical production and can interfere with diagnostic assays. Finally, current "Cohn" products are made by a process that has changed little in over 50 years and there are many inefficient or inconsistent practices built into the procedure. Proliant began unprecedented study into the current methods of BSA production and the reasons for differences in product suitability. For six years, the company has been researching the production and performance of Bovine Serum Albumin, developing and perfecting more modern fractionation methods. We have learned to remove and isolate the other plasma components, similar to Cohn's original process, but using cutting-edge separation techniqu |
2楼2008-10-26 01:01:48
3楼2008-10-26 11:26:05
