LOINCActiveBoth

LOINC Code 55974-0: IgG Immune diff (S) [Mass/Vol]

55974-0 is a LOINC code used to identify IgG Immune diff (S) [Mass/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component IgG. It is commonly used with the system or sample type Ser.

Reviewed by HealthAssure Clinical TeamUpdated 25 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component IgG. It is commonly used with the system or sample type Ser.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Both
  • Method: Immune diffusion

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • IgG [Mass/volume] in Serum by Immune diffusion (ID)
  • IgG
  • Chemistry; ID; Imm; Immune globulin G; Immunodiff; Immunodiffusion; Immunoglobulin G; Imun; Imune; Level; Mass concentration; Point in time; QNT; Quan; Quant; Quantitative; Random; Serum; SR

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

IgG Immune diff (S) [Mass/Vol]IgG [Mass/volume] in Serum by Immune diffusion (ID)IgG Ser ID-mCncIgGCHEMIgG, BloodMCnc

Frequently asked questions

Code details

Code55974-0
SystemLOINC
Display nameIgG Immune diff (S) [Mass/Vol]
DescriptionIgG
Short nameIgG Ser ID-mCnc
ComponentIgG
PropertyMCnc
TimingPt
System (specimen)Ser
ScaleQn
MethodImmune diffusion
ClassCHEM
Example unitsg/L
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.29
Last changed2.70

Consumer names

IgG, Blood

Part names

IgGMCncPtSerQnImmune diffusionMass ConcentrationPoint in time (spot)SerumImmune diffusion (ID)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 55974-0 | HealthAssure