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Human Platelet Lysate (or hPL) is a substitute supplement for fetal bovine serum (FBS) in experimental and clinical cell culture. It corresponds to a turbid, light-yellow liquid that is obtained from human blood platelets after freeze/thaw cycle(s). The freeze/thaw cycle causes the platelets to lyse, releasing a large quantity of growth factors necessary for cell expansion. == Process == Platelets have a life span of 5 to 9 days. Because of this, the U.S. Food and Drug Administration (FDA) expires transfuse-able platelets 5 days post-collection. Typically, hPL is produced from expired platelets that have been stored in frozen conditions no later than 7 days post-collection. hPL is created from single or pooled donor-donated platelets isolated from whole blood or by apheresis, distributed in a standard platelet collection bag. There are some differences between hPL manufacturing protocols, but they all share the same core of being frozen at very low temperatures and thawed. This process may be repeated two or three times to cause complete platelet lysis. The resultant hPL can then undergo different manufacturing steps to achieve multiple grades of hPL. The most common form of hPL undergoes few processing steps, producing a product made of the supernatent following the freeze/thaw process. The included clotting factors require to add heparin to the cell culture media to prevent coagulation during incubation. Another form of hPL is one that can be used in cell culture without the need of heparin, or any anticoagulant, addition. This grade of hPL goes through further manufacturing steps to inhibit the effect the clotting factors have. Many labs around the world are creating small amounts of hPL to suit their laboratory needs. The disadvantages of this process are: cost and consistency. When creating small batches of hPL (single or few donors pooled), the lot-to-lot consistency of the hPL becomes variable. Large-scale manufacturing by pooling many platelet donors is a necessity to mitigate the donor-to-donor variability. Consistency is a top priority for experimental designs to provide reproducible results. Platelet lysate is commonly used for supplementation of basal media in mesenchymal stem cells culture. Prior the use, the pathogen inactivation process is recommended to prevent pathogen transmission. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Platelet lysate」の詳細全文を読む スポンサード リンク
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