Product Description
Normal guinea pig serum is tested for complement activity and certified to possess functional classical and alternative pathways of activation. GPS was prepared from male mixed breed guinea pigs.Each sample of blood was collected without anticoagulants and after coagulation the liquid portion was separated by centrifugation.Serum was filtered through a 0.22 µm filter, aliqoted and frozen at -80oC.
Guinea pig complement was used in the first few decades of complement research because it exhibits 4 to 5-fold higher titers of classical pathway activity against EA in CH50 assays than human serum.In addition, a C4 deficient line of guinea pigs (CompTech product C4-D guinea pig serum #A305) was discovered in 1970 allowing unique research to be done (e.g. the discovery or re-discovery of the alternative pathway) (Ellman, L., et al. (1970)).Later a line of C2 deficient guinea pigs was also discovered (Bitter-Suermann, D., et al. (1981)).In addition, GPS is considerably more stable that mouse or rat complement making it easier to work with.
All testing for complement activity in GPS was performed on the once frozen and subsequently thawed samples to guarantee that the functional activity reported is what customers will receive when their samples are thawed.Complement activity is stable for several years if GPS is stored at -70oC or below continuously.Guinea pig complement is not as stable as human complement in normal human serum and some degradation of activity may be observed if the GPS is allowed to remain thawed for more than a few hours even if it is kept on ice.While it is better to freeze it overnight below -70 oC, some loss of activity may occur following this additional freeze thaw cycle.
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Complement Technology的C1是级联反应中的第一个补体成分，称为补体经典途径。C1与抗原结合的抗体（免疫复合物）结合并被其激活，从而产生引发级联反应的蛋白酶。C1实际上是钙依赖性复合物中结合在一起的三种不同蛋白质（C1q，C1r和C1s）的非共价复合物。C1q通过其六个臂中的两个或多个与IgG或IgM的Fc结构域结合。多臂与免疫复合物的结合被认为会引入压力，从而导致复合物中的两个C1r蛋白（蛋白酶酶原）自身激活，从而产生两种活性的C1r丝氨酸蛋白酶（Morikis，D.和Lambris，JD（2005））。 。这些激活的C1r亚基裂解并激活复合物中的两个C1s蛋白酶酶原。活化的C1裂解补体成分C4，释放出C4a，并启动C4b与活化表面的共价连接。活化的C1也切割C2，并且C2的较大片段结合至表面附着的C4b，形成C4b，C2a，其为经典途径的C3 / C5转化酶。
