LOINCActiveObservation

LOINC Code 13398-3: Histidine (Amn fld) [Mass/Vol]

13398-3 is a LOINC code used to identify Histidine (Amn fld) [Mass/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 Histidine. It is commonly used with the system or sample type Amnio fld.

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 Histidine. It is commonly used with the system or sample type Amnio fld.

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

What it does not mean

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

Key facts

  • Histidine [Mass/volume] in Amniotic fluid
  • Histidine
  • AF; Amn; Amn fl; Amnio; Amniotic flu; Amniotic fluid; Chemistry; Formiminoglutamic Acidemia; His; Histidinemia; Level; Mass concentration; Point in time; QNT; Quan; Quant; Quantitative; Random

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

Histidine (Amn fld) [Mass/Vol]Histidine [Mass/volume] in Amniotic fluidHistidine Amn-mCncHistidineCHEMHistidine, Amniotic fluidMCnc

Frequently asked questions

Code details

Code13398-3
SystemLOINC
Display nameHistidine (Amn fld) [Mass/Vol]
DescriptionHistidine
Short nameHistidine Amn-mCnc
ComponentHistidine
PropertyMCnc
TimingPt
System (specimen)Amnio fld
ScaleQn
ClassCHEM
Example unitsmg/dL
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0j-a
Last changed2.42

Consumer names

Histidine, Amniotic fluid

Part names

HistidineMCncPtAmnio fldQnMass ConcentrationPoint in time (spot)Amniotic fluid

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 13398-3 | HealthAssure