[Storage stability of 14 plasma proteins in ACD-AG banked blood]

In summarizing the results it can be stated that, when stored, the proteins haemopexin, alpha 1-antichymotrypsin, alpha 1-antitrypsin, which are rich of neuraminic acid, and IgA are predominantly characterized by a diminution of electrophoretic mobility and thus of concentration in electro-immunodiffusion, with the neuraminic acid content decreasing at the same time. These changes are probably caused by bacteria and/or virus neuraminidase. The decrease of pre-albumin concentration to be observed in radial-immunodiffusion and electro-immunodiffusion is caused by other mechanisms because pre-albumin contains no neuraminic acid. In accordance with these findings the most important changes of single proteins which can be measured by our equipment concern the percentage of non-proteins, whereas the antigen binding places will remain relatively stable during storage (ep. findings of radial immunodiffusion).