LOINCActiveObservation

LOINC Code 324-4: Methicillin Disk diffusion (KB) [Susc]

324-4 is a LOINC code used to identify Methicillin Disk diffusion (KB) [Susc] 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 Methicillin. It is commonly used with the system or sample type Isolate.

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 Methicillin. It is commonly used with the system or sample type Isolate.

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: Observation
  • Method: Agar diffusion

What it does not mean

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

Key facts

  • Methicillin [Susceptibility] by Disk diffusion (KB)
  • Methicillin
  • ANTIBIOTIC SUSCEPTIBILITIES; AST; Celbenin; Dimethoxypenicillin; Disk diffusion; ID; Infectious Disease; InfectiousDisease; Islt; Isol; KB; Kirby-bauer; Metacillin; Metin; Point in time; Random; Staficyn; Staphicillin; Sus; Suscept; Susceptibilities; Susceptibility; Susceptibilty

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

Methicillin Disk diffusion (KB) [Susc]Methicillin [Susceptibility] by Disk diffusion (KB)Methicillin Islt KBMethicillinABXBACTSusceptibility to MethicillinSusc

Frequently asked questions

Code details

Code324-4
SystemLOINC
Display nameMethicillin Disk diffusion (KB) [Susc]
DescriptionMethicillin
Short nameMethicillin Islt KB
ComponentMethicillin
PropertySusc
TimingPt
System (specimen)Isolate
ScaleOrdQn
MethodAgar diffusion
ClassABXBACT
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.19

Consumer names

Susceptibility to Methicillin

Part names

MethicillinSuscPtIsolateOrdQnAgar diffusionSusceptibility (microorganisms)Point in time (spot)Disk diffusion (KB)

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 324-4 | HealthAssure