Important Note
**Effective 06/2025, Willis Knighton switched in-house testing from TSH to TSH, Sensitive.**
As part of an enterprise-wide implementation of Beckman Coulter Diagnostics chemistry and immunoassay testing, Willis Knighton Health converted to 3rd generation testing of Thyroid Stimulating Hormone (TSH) on 6/3/2025, making our new TSH test highly sensitive. As methods achieving third-generation sensitivity have become available, TSH measurements are also used to identify subclinical or latent hypothyroidism or hyperthyroidism. Highly sensitive TSH tests employ advanced laboratory techniques that allow for the detection of lower concentrations of TSH in the blood. Traditional TSH tests can sometimes miss subtle changes in hormone levels that might indicate early-stage thyroid dysfunction. This is where highly sensitive TSH testing comes into play. The highly sensitive TSH test is designed to detect even minor fluctuations in TSH levels, providing a more accurate picture of thyroid function. Third generation methods for TSH measurement are defined as achieving a functional sensitivity of 0.01-0.02 μIU/mL (mIU/L) with an interassay %CV ≤ 20%.

Infectious
Additional Codes
MEDITECH MNEMONIC:
TSH
Specimen Requirements
Preferred Specimen:
1mL Lithium Heparin Plasma
Acceptable Specimen:
1mL Serum from a gel or non-gel tube
Minimum Volume:
0.5mL plasma or serum (volume does not include repeat or reflexed testing)
Transport Temperature/Stability
Transport Container:
Transport Tube
Preferred Transport Temperature:
Refrigerated
Specimen Stability (after centrifugation):
Ambient: <18 hours
Refrigerated: <7 days
Frozen: >7 days
Setup Schedule:
SUN-SAT