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Test Code ACHS Acetylcholinesterase, Erythrocytes

Reporting Name

Acetylcholinesterase, RBC

Useful For

Detecting effects of chronic or remote (months) past exposure to cholinesterase inhibitors (organophosphate insecticide poisoning)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Whole Blood EDTA

Advisory Information

For testing succinylcholine sensitivity to anesthesia, order PCHE1 / Pseudocholinesterase, Total, Serum.

Shipping Instructions

Specimen must arrive within 72 hours of collection.

Necessary Information

Date of collection is required.

Specimen Required

Container/Tube: Lavender top (EDTA)

Specimen Volume: 4 mL

Specimen Minimum Volume

2.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated

Reference Values

31.2-61.3 U/g of hemoglobin

Day(s) and Time(s) Performed

Friday; 10 a.m.

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
ACHS Acetylcholinesterase, RBC 49230-6


Result ID Test Result Name Result LOINC Value
ACHSR Acetylcholinesterase, RBC 49230-6

Clinical Information

Erythrocyte acetylcholinesterase (AChE) activity is measured to evaluate possible exposure to organophosphate insecticides. Organophosphates act by irreversible inhibition of AChE. Inhibition of AChE in humans causes a variety of acute symptoms including dizziness, nausea, difficulty breathing, and even death. The presence and severity of these symptoms depend, in part, on the degree of AChE depression.


Occupational pesticide handlers are at an elevated risk for exposure to these chemicals through skin contact, inhalation, or accidental ingestion. Organophosphate intoxication can be a result of one or more high exposure events or through chronic lower-level exposure.


Both serum and erythrocyte cholinesterase activity are inhibited by these insecticides, which are among the most commonly used pesticides in the United States. The half-life of serum cholinesterase (eg. pseudocholinesterase) is about 8 days, while the half-life of AChE in erythrocytes is between 2 and 3 months. Therefore, erythrocyte AChE is an indicator of chronic and temporally distant exposures to organophosphates.

Analytic Time

4 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK

NY State Approved


Method Name

Spectrophotometric-Thiocholine Production