Allow SST to clot in an upright position for at least 30 minutes, then centrifuge sample within 2 hours of collection. Transfer serum to a plastic transport tube. Freeze.
Sample should be collected between 15 minutes and 3 hours after the event suspected to have caused mast cell activation.
When multiple tests are ordered, submit separate tube for this test.
Note: This test can be performed on post-mortem samples.