Method:
(1) Perform testing after standardizing the specimen volume, tube size and conditions of centrifugation as much as possible.
(2) Place a sample of serum kept warm since collection into a warmed tube.
(3) Place the sample into the cold (4°C) until the cryoprecipitate has formed.
(4) Centrifuge the tube in the cold (4°C) until the cryoprecipitate has formed a pellet in the tube.
(5) Measure the length of the cryoprecipitate pellet and total length of the serum in the tube while keeping the tube cold.
cryocrit in percent =
= (length of cryoprecipitate band in mm) / (length of serum in tube in mm) * 100%
Limitations:
• The cryocrit should not be used to compare patients.
• The cryoprecipitate pellet is not washed or processed and it can be affected by specimen handling.
If a more accurate measurement of the cryoprotein is needed, then the cryoprecipitate should be washed at 4°C and reheated in a fixed volume until the protein has become soluble again, after which it can be analyzed.
