What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 45042-9: Unsp microorganism Ag IF Nom (Specimen)

Name: LOINC Code 45042-9: Unsp microorganism Ag IF Nom (Specimen)
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

45042-9 is a LOINC code used to identify Unsp microorganism Ag IF Nom (Specimen) 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 XXX microorganism Ag. It is commonly used with the system or sample type XXX.

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 XXX microorganism Ag. It is commonly used with the system or sample type XXX.

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: IF

What it does not mean

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

Key facts

XXX microorganism Ag [Identifier] in Specimen by Immunofluorescence
XXX microorganism Ag
ACIF; Anticomplement Immunofluorescence; Antigen; Antigens; DFA; FA; Fluorescent antibody; Fluoresent; ID; Identity or presence; IFA; Immune fluorescence; Immunoflour; Immunofluor; Immunofluorescence; Infectious Disease; InfectiousDisease; Microbiology; Microorganisms; Misc; Miscellaneous; Nominal; Org; Organism; Organisms; Other; Other microorg; Point in time; Random; Spec; Time Resolved Fluorescence; To be specified in another part of the message; TRF; UniversalLabOrders; Unspecified

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.

Related SNOMED CT concepts

705114005SNOMED CT mapping for Unsp microorganism Ag IF Nom (Specimen) (45042-9)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

Unsp microorganism Ag IF Nom (Specimen)XXX microorganism Ag [Identifier] in Specimen by ImmunofluorescenceOther microorg Ag Spec IFXXX microorganism AgMICROUnsp microorganism antigen, SpecimenPrid

Frequently asked questions

Code details

Code45042-9

SystemLOINC

Display nameUnsp microorganism Ag IF Nom (Specimen)

DescriptionXXX microorganism Ag

Short nameOther microorg Ag Spec IF

ComponentXXX microorganism Ag

PropertyPrid

TimingPt

System (specimen)XXX

ScaleNom

MethodIF

ClassMICRO

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.17

Last changed2.69

Consumer names

Unsp microorganism antigen, Specimen

Part names

XXX microorganism AgPridPtXXXNomIFPresence or IdentityPoint in time (spot)Immunofluorescence (IF)

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.