LOINCActiveBoth

LOINC Code 4550-0: Hemoglobin A2 Chromatography column (Bld) [Moles/Vol]

4550-0 is a LOINC code used to identify Hemoglobin A2 Chromatography column (Bld) [Moles/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 Hemoglobin A2. It is commonly used with the system or sample type Bld.

Reviewed by HealthAssure Clinical TeamUpdated 21 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 Hemoglobin A2. It is commonly used with the system or sample type Bld.

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: Chromatography.column

What it does not mean

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

Key facts

  • Hemoglobin A2 [Moles/volume] in Blood by Chromatography column
  • Hemoglobin A2
  • Blood; Column Chrom; Haemoglobin; Hb; HEMATOLOGY/CELL COUNTS; Hgb; Hgb A2; Level; Point in time; QNT; Quan; Quant; Quantitative; Random; Substance concentration; WB; Whole blood

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

Hemoglobin A2 Chromatography column (Bld) [Moles/Vol]Hemoglobin A2 [Moles/volume] in Blood by Chromatography columnHgb A2 Bld Column Chrom-sCncHemoglobin A2HEM/BCHemoglobin A2, BloodSCnc

Frequently asked questions

Code details

Code4550-0
SystemLOINC
Display nameHemoglobin A2 Chromatography column (Bld) [Moles/Vol]
DescriptionHemoglobin A2
Short nameHgb A2 Bld Column Chrom-sCnc
ComponentHemoglobin A2
PropertySCnc
TimingPt
System (specimen)Bld
ScaleQn
MethodChromatography.column
ClassHEM/BC
Example unitsmmol/L
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.73

Consumer names

Hemoglobin A2, Blood

Part names

Hemoglobin A2SCncPtBldQnChromatography.columnSubstance ConcentrationPoint in time (spot)BloodChromatography column

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 4550-0 | HealthAssure