Dibucaine number

Alphabetical Test listing

Dibucaine number-994

Test name:

Dibucaine number

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

Dibucaine inhibition

Useful for:

Assess the presence of homozygous or heterozygous “atypical” cholinesterase variant, in patients who have low result of serum or plasma cholinesterase assay, and may be at risk of apnea when given succinylcholine muscle relaxant.

Limitations:

No single simple test currently exists that can detect all enzyme variants.

Patient preparation information:

Do not collect within 24 hours of administration of muscle relaxant

Specimen type:

Serum

Collection container:

Gold serum separator (SST) tube

Volume:

0.5 mL

Minimum volume:

0.2 mL

Collection instructions:

Immediately following collection, thoroughly mix sample by gently inverting 5 times

Processing instructions:

Allow sample to clot for a minimum of 30 minutes
Spin within two (2) hours of sample collection
Transfer serum to a Transfer vial/tube with cap - 12mL (LabCorp), labelled as serum

Transport container:

Transfer vial/tube with cap - 12mL (LabCorp)

Alternate collection container:

Red serum vial/tube - 5 mL

Transport and stability:

Ambient (preferred) - 14 days

Refrigerated - 14 days

Frozen - 14 days

Freeze/thaw cycles - stable x3

Reason for rejection:

Serum not separated from cells
Frozen whole blood received
Hemolysis

Performing lab:

LabCorp Burlington (081513): R-NX

Days set up:

Su - Fr

TAT:

3 - 5 days

Method:

Cholinesterase by spectrophotometry (Ellman) with dibucaine inhibition

Reference ranges:

Normal: 70% - 90% inhibition
Heterozygotes: 30% - 70% inhibition
Homozygotes: 0% - 30% inhibition

CPT codes:

82638

LOINC code:

Result 39354-6

Date created:

05/30/2019

Revised date:

10/22/2026

Review date:

10/22/2026