One 7.5 mL serum separator tube (SST). Also acceptable: One 5 mL red top tube. Patient must be fasting for 10 hours or longer for basal serum gastrin levels.
Handling:
Allow to clot, centrifuge and separate serum from cells within one hour. Freeze immediately. Allow no more than one freeze/thaw cycle. If multiple tests are ordered, send a separate specimen for this test.
Stability:
4 hours refrigerated at 2-8° C or 30 days frozen at -20° C.
Standard Volume:
1 mL serum.
Minimum Volume:
0.5 mL serum.
Transport:
Frozen on dry ice.
Comments:
Measurement of the major forms of gastrin or immunoreactive gastrin in serum is the definitive test for the diagnosis of gastrinoma in patients with gastric acid hypersecretion.
Rejection Criteria:
Hemolysis; lipemia; specimen which has been frozen and thawed more than once.