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.

LOINCActiveObservation

LOINC Code 50728-5: Serotonin release 0.1 IU/mL heparin.unfractionated Qn (S)

Name: LOINC Code 50728-5: Serotonin release 0.1 IU/mL heparin.unfractionated Qn (S)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:34.496Z

50728-5 is a LOINC code used to identify Serotonin release 0.1 IU/mL heparin.unfractionated 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 Serotonin release 0.1 IU/mL heparin.unfractionated. 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 Serotonin release 0.1 IU/mL heparin.unfractionated. 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: Observation

What it does not mean

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

Key facts

Serotonin release 0.1 IU/mL heparin.unfractionated [Units/volume] in Serum

Serotonin release 0.1 IU/mL heparin.unfractionated

Resulted as percentage of specific serotonin release(cpm test - cpm spont)/(cpm max - cpm spont) x 100, where cpm "spont" is the spontaneous release of [3H]serotonin from cells incubated in absence of antibodies, and cpm "max" is the maximum release of [3H]serotonin from cells lysed using 1% Triton X-100.

5-HT; 5-hydroxytryptamine; 5-hydroxytryptophane; Arbitrary concentration; C10H12N2O; Enteramine; Hep; Hepar; Heparin dependent platelet antibody; Heparn; Point in time; QNT; Quan; Quant; Quantitative; Random; Serology; Serotonin release assay; Serum; SR; SRA; SRA 0.1IU; SRA 0.1IU/mL UFH; SRA low 0.1; SRA low dose heparin; UFH

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

Serotonin release 0.1 IU/mL heparin.unfractionated Qn (S)Serotonin release 0.1 IU/mL heparin.unfractionated [Units/volume] in SerumSRA 0.1IU/mL UFH Ser-aCncSerotonin release 0.1 IU/mL heparin.unfractionatedSEROSerotonin Release 0.1 IU/mL Heparin.unfractionated, BloodACnc

Frequently asked questions

Code details

Code50728-5

SystemLOINC

Display nameSerotonin release 0.1 IU/mL heparin.unfractionated Qn (S)

DescriptionSerotonin release 0.1 IU/mL heparin.unfractionated

Short nameSRA 0.1IU/mL UFH Ser-aCnc

ComponentSerotonin release 0.1 IU/mL heparin.unfractionated

PropertyACnc

TimingPt

System (specimen)Ser

ScaleQn

ClassSERO

Example units%

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.22

Last changed2.73

Consumer names

Serotonin Release 0.1 IU/mL Heparin.unfractionated, Blood

Part names

Serotonin release 0.1 IU/mL heparin.unfractionatedACncPtSerQnArbitrary 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.