Parathyroid Hormone (PTH), Intact

Cleveland HeartLab P, Test

CPT Code: 83970
Order Code: C309
ABN Requirement:  No
Synonyms: PTH Intact; PTHI
Specimen: EDTA Plasma or Serum
Volume: 0.5 mL
Minimum Volume: 0.2 mL
Container: EDTA (Lavender Top) tube or Gel-barrier tube (SST, Tiger Top)


EDTA Plasma:

  1. Draw and gently invert 8 to 10 times.
  2. Centrifuge for 10 minutes.
  3. Pre-squeeze transfer pipet bulb and draw off approximately 2/3 of the upper plasma layer.
    Note: This ensures that the buffy coat and red cells remain undisturbed.
  4. Aliquot plasma into labeled transport tube and cap tightly. Discard original tube.
  5. Store transport tube refrigerated at 2-8°C until ready to ship.


  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Special Information: The supplementation of high biotin levels, exceeding the recommended daily allowance of 0.03 mg, could lead to incorrect blood test results with immunoassays that are based on biotin-streptavidin interactions. Clinicians should consider biotin interference as a source of error, when clinically suspicious of the laboratory result.

Transport: Store EDTA plasma or serum at 2°C to 8°C after collection and ship the same day per packaging instructions provided with the Cleveland HeartLab shipping box.


Ambient (15-25°C): EDTA Plasma-1 day; Serum-N/A
Refrigerated (2-8°C): EDTA Plasma-3 days; Serum-1 day
Frozen (-20°C): 6 months
Deep Frozen (-70°C): 6 months

Causes of Rejection: Hemolyzed samples; specimens other than EDTA plasma or serum; improper labeling; samples not stored properly; samples older than stability limits; hemolyzed samples

Methodology: Chemiluminescence Immunoassay (CLIA)

Turn Around Time: 1 to 5 days

Reference Range:

Age pg/mL
All Ages 11.5-78.4


Intended Use: A parathyroid hormone test can be used to determine the cause of calcium or phosphorus imbalances, to evaluate bone disorders and to diagnose and differentiate parathyroid dysfunction including primary and secondary hyperparathyroidism and hypoparathyroidism. A parathyroid hormone test may also be ordered for individuals with osteoporosis without an obvious cause, that is severe, or that is unresponsive to treatment.

Limitations: In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies, streptavidin or ruthenium can occur.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.