General Information

UPHSM LIS Test #: 6420
Testing Time:
Testing Lab: Labcorp

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume: 5 (1) mL
Temperature: Refrigerate
Tube Type: Lavendar-top (EDTA) Tube
Collection Info:
Specimen: Whole blood

Volume: 5 mL

Minimum Volume: 1 mL

Container: Lavender-top (EDTA) tube

Storage Instructions: Room temperature; do not separate.

Causes for Rejection: Plasma specimen; anticoagulants other than EDTA; frozen whole blood received; hemolysis

Limitations: Values decrease as erythrocytes become senescent.

Specimen Acceptability

Whole blood


Spectrophotometry (Ellman) − kinetic

Clinical Utilities

Erythrocyte cholinesterase is measured to diagnose organophosphate and carbamate toxicity and to detect atypical forms of the enzyme. Cholinesterase is irreversibly inhibited by organophosphate insecticides and reversibly inhibited by carbamate insecticides. Serum or plasma pseudocholinesterase is a better measure of acute toxicity, while erythrocyte levels are better for chronic exposure. (Serum level returns to normal prior to normalizing of red cell level).

CPT Codes


* 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.

Reference Range

5300-10,000 IU/L