Cryoglobulin and Cryofibrinogen Panel, Serum and Plasma
Method Description Describes how the test is performed and provides a method-specific reference
The normal proteins of plasma and serum do not precipitate in the cold. An aliquot of plasma and of serum are incubated for 24 hours at 1 degree C. If a precipitate develops in the serum, the specimen is centrifuged and the percent precipitate is reported. Negative specimens are kept at 1 degree C for 7 days and rechecked. All positive cryoglobulins are analyzed by immunofixation to determine if the precipitate is a monoclonal protein, polyclonal protein, or a mixed cryoglobulin. Precipitates that occur in plasma and not serum are reported as positive for cryofibrinogen. Cryofibrinogen-positive specimens are not quantitated or immunotyped. Slowly forming fibrin clots (as may occur in hemophilia) are distinguished from cryoprecipitates by their inability to redissolve on warming.(Lerner AB, Watson CJ: Studies of cryoglobulins. I. Unusual purpura associated with the presence of a high concentration of cryoglobulin [cold precipitatable serum globulin]. Am J Med Sci 1947;214:410-415)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 4 p.m.