Order Code LAB1575 Glucagon, Plasma
Reporting Name
Glucagon, PUseful For
Diagnosis and follow-up of glucagonomas and other glucagon-producing tumors
Assessing diabetic patients with problematic hyper- or hypoglycemic episodes (extremely limited utility)
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Plasma EDTASpecimen Required
Patient Preparation: Fasting (8 hours)
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Pre-chill lavender top (EDTA) tube at 4° C before drawing the specimen.
2. Draw blood into the pre-chilled tube and process as follows:
 a. Chill filled tube in wet ice for 10 minutes.
 b. Centrifuge in a refrigerated centrifuge or in a pre-chilled centrifuge carrier.
 c. Immediately after centrifugation, aliquot plasma into a plastic vial and freeze.
Specimen Minimum Volume
0.45 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma EDTA | Frozen | 90 days |
Reference Values
≤6 hours: 100-650 pg/mL
1-2 days: 70-450 pg/mL
2-4 days: 100-650 pg/mL
4-14 days: declining gradually to adult levels
>14 days: ≤80 pg/mL (range based on 95% confidence limits)
Glucagon levels are inversely related to blood glucose levels at all ages. This is particularly pronounced at birth and shortly thereafter, until regular feeding patterns are established. This explains the higher levels immediately after birth, which then first fall as the glucagon release mobilizes the infant's glucose stores, then rise again as stores are depleted, finally normalizing towards adult levels as regular feeding patterns are established.
For International System of Units (SI) for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Day(s) Performed
Tuesday, Thursday
CPT Code Information
82943
Method Description
Big plasma glucagon, which is considered to be biologically inactive, is extracted using ethanol and removed prior to assay of the specimen. Following ethanol extraction, glucagon reacts with an anti-glucagon antibody that is attached to magnetic beads. After incubation and washing, a second detection antibody is added and attaches to any bead-bound glucagon, forming a sandwich assay. A streptavidin-phycoerythrin (SPE) tag binds to the glucagon-antibody complex. Laser-based fluorescent analysis of the resulting glucagon-antibody-SPE complex is performed on the Luminex 200 instrument.(Unpublished Mayo method)
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | OK |
Gross icterus | OK |
Method Name
Immunoassay
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.