We require at least 0.5mL of serum for the FT4 test. If we receive anything less than this we will be unable to perform the testing.
So please ensure you send us as close to 1mL of blood as possible (red top, gel or EDTA tube). If you require other testing on the same sample, a bigger volume will be required.
If you’re ever unsure, just give your local laboratory a call (0800 GRIBBLES) and they will be happy to advise!