Serum/plasma tests
Hormones
Steroid Hormones
Androstenedione
Bioavailable testosterone
Cortisol
DHEA-S
Dihydrotestosterone (DHT) (TOS)
Estradiol
Estradiol-HRT
17-OH progesterone (TOS)
Pregnenolone
Progesterone
Testosterone
Peptide Hormones
Follicle Stimulating Hormone (FSH)
Insulin (TOS)
Luteinizing Hormone (LH)
Secretin (TOS)
Sex Hormone Binding Globulin (SHBG)
Thyroid Stimulating Hormone (TSH)
Vasoactive Intestinal Polypeptide (VIP) (TOS)
Other Hormones
Free Triiodothyronine (FT3)
Free Thyroxine (FT4)
Triiodothyronine (T3)
Thyroxine (T4)
Other

TOS - To be offered shortly


Tests › Serum/plasma tests › Hormones › Steroid Hormones › Estradiol

Estradiol

Significance
Estradiol is the most biologically active form of all the naturally occurring estrogens and the most important one. In females, during reproductive years, it is largely is produced by the ovaries. Smaller amounts are also produced by the adrenal glands and from metabolism of testosterone in the peripheral circulation. Estradiol is responsible for development of sex organs and characteristics in females. It is also found in males, but in much smaller concentrations.
Estradiol circulates mostly bound to estrogen binding globulin (also referred to as SHBG) with a smaller fraction loosely bound to albumin. A small percentage circulates unbound to proteins (free form). The free and weakly bound are considered biologically active forms. Estradiol levels are most commonly used to evaluate ovarian function, and in males to diagnose the cause of gynecomastia. Estradiol is also used to monitor menopausal hormone replacement therapy.

Analysis
Determination of Estradiol is performed by Enzyme Immunoassay.

Patient Preparation
Please note: steroid compounds, ACTH, Gonadotropin, or estradiol containing medications all influence estradiol levels. Please provide patient gender, age, and information regarding medications that may influence estradiol levels. Indicate if patient is on hormone replacement. Samples drawn in the morning are preferred.

Specimen requirements
Collect blood specimen into plain or redtop evacuated tube. Centrifuge and separate serum from cells (plain tube). Volume requested: at least 1 mL serum. Minimum volume: 0.5 mL

Shipping Instructions
Ship specimen at ambient temperatures. For long distance shipping, ship with ice packs.

Additional information
http://labtestsonline.org/understanding/analytes/estrogen/test.html
http://www.nlm.nih.gov/medlineplus/ency/article/003711.htm