Lab Test : Free T4

Print this page Bookmark and Share
Alternate:Free thyroxine; FT4
Includes:Free T4
Phone:(937) 641-3428
SQ Code:FT4
Available:Mon - Fri, first shift only
Turnaround:24 hours
Volume:0.7 mL
Container:4 mL red top tube
Temperature:Transport to lab within 30 minutes.
Rejection:Samples held at room temperature for more than 8 hours.
Normal:1 day: 0.74-2.52 ng/dL
4 days: 0.74-2.10 ng/dL
1 month: 0.77-2.02 ng/dL
1 year: 0.89-1.80 ng/dL
Uses:Thyroid evaluation.
Limitations:The anticonvulsant drug phenytoin may interfere with the total and free T4 levels due to competition for TBG binding sites. FT4 values may be decreased in patients with non-thyroid conditions and in patients taking carbamazepine.
Method:Competitive chemiluminescence immunoassay

Make a referral

Phone: 937-641-4000
Fax referral forms: 937-641-4500, 24 hours
Toll-free fax: 1-866-891-6941
Hours: 7:30 am to 7:00 pm, Monday through Friday

Download our fax referral form or make a referral online.

Pediatric Link

Finding the latest trusted child health and safety information doesn't have to be hard. Pediatric Link, Dayton Children's e-newsletter offers timely and up-to-date information for health care professionals from the experts you trust at Dayton Children's.

Sign up

The Right Experts

Just right for all kids


The Children's Medical Center of Dayton Dayton Children's
The Right Care for the Right Reasons

One Children's Plaza - Dayton, Ohio - 45404-1815