The normal proteins of serum do not precipitate in the cold. An aliquot of serum is 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.(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)
Monday through Friday; 4 pm
Negative (Positive reported as percent) If Positive after 1 or 7 days, immunotyping of the cryoprecipitate is performed at an additional charge.