Table 1 Characteristics of commonly used commercial assays for GH (according to manufacturers instructions/kit inserts available to the authors or according to published data). Calibration has changed for several assays in recent years, and the process is ongoing. To the best of the authors knowledge the assays listed here have uniformly adopted the latest recombinant standard for all countries. The list of assays is not complete. Additional hGH assays exist, including an unknown number of in-house assays. (modified from [3]

Siemens

Immulite 2000

Two-site Chemilumminescent immunometric assay

Not provided

0.05 to 40 ng/mL Analytical sensitivity: 0.01 ng/mL

Serum

ng/mL × 3.0 ➔mIU/L

Diasorin

Liaison hGH

Chemiluminescent sandwich immunoassay

Not provided

0.009–80 ng/mL

Serum

Beckmann-Coulter

Access Ultrasensitive hGH

Automated immunometric assay, Chemiluminescence

See comment

0.002–35 ng/mL (μ/L)

Serum or plasma (heparin)

Cross reaction analysed with GH 8 ng/mL for 20 K-GH: − 2542%

IDS

iSYS hGH

Chemilumminescent assay

22kD GH: 100%

0.05–100 ng/mL

Serum or plasma (heparin or EDTA)

Do not cross react with substances in these concentrations: 20 K-GH (10 ng/mL); placental GH (200 ng/mL); HPL (10,000 ng/mL); prolactin (40.000 ng/mL); pegvisomant (50,000 ng/mL); biotin 300 nmol/L); GHBP: 140 ng/mL. ng/mL × 3.0=μIU/mL

DIASource

hGH IRMA

Immunometric assay enzyme amplified sensitivity

Not provided

1–120 ng/mL

Sensitivity: ng/mL

Serum, plasma

Conversion factor: 1μIU = 0.33 ng

hGH EASIA

Enzyme-Immunoassay

Not provided

0.45–98 ng/mL

Sensitivity:0.17 ng/mL

Serum, plasma

Conversion factor: 1μIU = 0.33 ng

CisBio

hGH-RIACT

Immunoradiometric

Not provided

0.03–75 ng/mL

Serum

1 ng = 3μIU; do not cross react with prolactin and hPL. Cross reaction with 20kD GH is less than 5% for the concentration up to 3750 ng/mL (22kD GH proportional concentration above 24,000 ng/mL)