Results of the insulin-like growth factor-1 assay are to be used in conjunction with other clinical and laboratory data to assist the clinician in the assessment of growth disorders.
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R).
It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Immediatley following collection, mix sample by gently inverting 5 times
1. Allow sample to clot for a minimum of 30 minutes
2. Spin within two (2) hours of sample collection
Gold serum separator (SST) tube
Refrigerated (preferred) - 7 days
Ambient - 3 days
Frozen - 90 days
Freeze/thaw cycles - stable x 3
Immunochemiluminometric assay (ICMA)
IGF-1: 79 - 259 ng/mL
IGF-1, Z score: -2.0 - +2.0