Laboratory Services

Immunoglobulin, IgM

Updated Test Information:

Test Description

Immunoglobulin, IgM

Synonym(s)

IgM Immunoglobulin

Test ID

IGM

General Information

IgM is the first specific antibody to appear in the serum after infection. It is capable of activating complement, thus helping to kill bacteria. After the infection has subsided, IgM levels sink at a relatively rapid rate compared to IgG. This fact is used in the differential diagnosis of acute and chronic infections by comparing specific IgM and IgG titers. If IgM is prevalent the infection is acute, whereas if IgG predominates the infection is chronic

Specimen Type

Serum

Specimen Requirements

SST

Alternate Specimen Type

Red, Li-heparin plasma, K2EDTA

Specimen Collection / Processing Instructions

SST - Separate serum or plasma from cells within 45 minutes of collection. If a red-top tube or green-top tube is used, transfer separated serum or plasma to a plastic transport tube.

Minimum Sample Volume

1 mL

Pediatric Min. Volume (if applicable)

500 uL

Additional Processing Details

Separate serum or plasma from cells within 45 minutes of collection. If a red-top tube or green-top tube is used, transfer separated serum or plasma to a plastic transport tube.

Stability

2 months at 15‑25 °C
4 months at 2‑8 °C
6 months at (-15)‑(-25) °C

Limitations

This test may not provide accurate results in patients with monoclonal gammopathy, due to individual sample characteristics which can be assessed by electrophoresis.

Methodology

Immunoturbidimetric

Estimated TAT

0-2 days

Testing Schedule

Monday-Saturday

CPT Code(s)

82784

Reference Range

0-<1 year	0-145 mg/dL
1-<4 years	19-146 mg/dL
4-<7 years	24-210 mg/dL
7-<10 years	31-208 mg/dL
10-<12 years	31-179 mg/dL
12-<14 years	35-239 mg/dL
14-<16 years	15-188 mg/dL
16-<19 years	23-259 mg/dL
Adults	40-230 mg/dL

Performing Lab

Incyte Diagnostics

LOINC Code(s)

2472-9