LOINCActiveBoth

LOINC Code 74521-6: Complement total hemolytic CH50 actual/normal IA (S) [Rel units/Vol]

74521-6 is a LOINC code used to identify Complement total hemolytic CH50 actual/normal IA (S) [Rel units/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 Complement total hemolytic CH50 actual/normal. It is commonly used with the system or sample type Ser.

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 Complement total hemolytic CH50 actual/normal. 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: IA

What it does not mean

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

Key facts

  • Complement total hemolytic CH50 actual/normal in Serum by Immunoassay
  • Complement total hemolytic CH50 actual/normal
  • Act/Nor; Comp; Complement CH50; Complmt; Control; EIA; ELFA; ELISA; Enzyme immunoassay; HEMATOLOGY/CELL COUNTS; IAA; MEIA; Point in time; QNT; Quan; Quant; Quantitative; Random; RlACnc; Serum; SR; SUDS; Tot; Total Hem Comp; Totl

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

Complement total hemolytic CH50 actual/normal IA (S) [Rel units/Vol]Complement total hemolytic CH50 actual/normal in Serum by ImmunoassayCH50 Act/Nor Ser IAComplement total hemolytic CH50 actual/normalHEM/BCComplement Total Hemolytic CH50 actual/normal, BloodRelACnc

Frequently asked questions

Code details

Code74521-6
SystemLOINC
Display nameComplement total hemolytic CH50 actual/normal IA (S) [Rel units/Vol]
DescriptionComplement total hemolytic CH50 actual/normal
Short nameCH50 Act/Nor Ser IA
ComponentComplement total hemolytic CH50 actual/normal
PropertyRelACnc
TimingPt
System (specimen)Ser
ScaleQn
MethodIA
ClassHEM/BC
Example units%
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.48
Last changed2.58

Consumer names

Complement Total Hemolytic CH50 actual/normal, Blood

Part names

Complement total hemolytic CH50 actual/NormalRelACncPtSerQnIARelative Arbitrary ConcentrationPoint in time (spot)SerumImmunoassay

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 74521-6 | HealthAssure