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 39775-2: Protoporphyrin Free (RBC) [Moles/Vol]

Name: LOINC Code 39775-2: Protoporphyrin Free (RBC) [Moles/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:26.653Z

39775-2 is a LOINC code used to identify Protoporphyrin Free (RBC) [Moles/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 Protoporphyrin.free. It is commonly used with the system or sample type RBC.

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 Protoporphyrin.free. It is commonly used with the system or sample type RBC.

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

Protoporphyrin Free [Moles/volume] in Red Blood Cells
Protoporphyrin.free
Chemistry; Dicarboxyl porphyrin; Dicarboxylporphyrin; Erythrocytes; FEP; FR; Free erythrocyte protoporphyrin; Hematology; Heme; Level; Non-protein bound; Point in time; Protoporph; Protoporphrn; Protoporphyrins; QNT; Quan; Quant; Quantitative; Random; Red blood cells; Red blood corpusles; Substance concentration

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

Protoporphyrin Free (RBC) [Moles/Vol]Protoporphyrin Free [Moles/volume] in Red Blood CellsFEP RBC-sCncProtoporphyrin.freeCHEMFree protoporphyrin, Red blood cellsSCnc

Frequently asked questions

Code details

Code39775-2

SystemLOINC

Display nameProtoporphyrin Free (RBC) [Moles/Vol]

DescriptionProtoporphyrin.free

Short nameFEP RBC-sCnc

ComponentProtoporphyrin.free

PropertySCnc

TimingPt

System (specimen)RBC

ScaleQn

ClassCHEM

Example unitsumol/L

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.15

Last changed2.73

Consumer names

Free protoporphyrin, Red blood cells

Part names

Protoporphyrin.freeSCncPtRBCQnProtoporphyrin FreeSubstance ConcentrationPoint in time (spot)Red Blood Cells

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.