LOINCActiveBoth

LOINC Code 6549-0: SLEV Ag Qn (S)

6549-0 is a LOINC code used to identify SLEV Ag Qn (S) 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 Saint Louis encephalitis virus Ag. 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 Saint Louis encephalitis virus Ag. 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

What it does not mean

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

Key facts

  • Saint Louis encephalitis virus Ag [Units/volume] in Serum
  • Saint Louis encephalitis virus Ag
  • Antigen; Antigens; Arbitrary concentration; Enc; Enceph; Encephalomyelitis; ID; Infectious Disease; InfectiousDisease; Microbiology; Point in time; QNT; Quan; Quant; Quantitative; Random; Serum; SLE virus; SLEV; SR; St Louis

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

SLEV Ag Qn (S)Saint Louis encephalitis virus Ag [Units/volume] in SerumSLEV Ag Ser-aCncSaint Louis encephalitis virus AgMICROSLEV antigen, BloodACnc

Frequently asked questions

Code details

Code6549-0
SystemLOINC
Display nameSLEV Ag Qn (S)
DescriptionSaint Louis encephalitis virus Ag
Short nameSLEV Ag Ser-aCnc
ComponentSaint Louis encephalitis virus Ag
PropertyACnc
TimingPt
System (specimen)Ser
ScaleQn
ClassMICRO
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0g
Last changed2.69

Consumer names

SLEV antigen, Blood

Part names

Saint Louis encephalitis virus AgACncPtSerQnArbitrary ConcentrationPoint in time (spot)Serum

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 6549-0 | HealthAssure