LOINCActiveObservation

LOINC Code 33053-0: Protoporphyrin (RBC) [Molar ratio]

33053-0 is a LOINC code used to identify Protoporphyrin (RBC) [Molar ratio] 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. 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. 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 [Molar ratio] in Red Blood Cells
  • Protoporphyrin
  • Chemistry; Dicarboxyl porphyrin; Dicarboxylporphyrin; Erythrocytes; Hematology; Heme; Point in time; Protoporph; Protoporphrn; Protoporphyrins; QNT; Quan; Quant; Quantitative; Random; Red blood cells; Red blood corpusles; Scrto; Substance concentration ratio; Substance ratio

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 (RBC) [Molar ratio]Protoporphyrin [Molar ratio] in Red Blood CellsProtopor RBC-sRtoProtoporphyrinCHEMProtoporphyrin, Red blood cellsSRto

Frequently asked questions

Code details

Code33053-0
SystemLOINC
Display nameProtoporphyrin (RBC) [Molar ratio]
DescriptionProtoporphyrin
Short nameProtopor RBC-sRto
ComponentProtoporphyrin
PropertySRto
TimingPt
System (specimen)RBC
ScaleQn
ClassCHEM
Example unitsumol/mol hb
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.09
Last changed2.73

Consumer names

Protoporphyrin, Red blood cells

Part names

ProtoporphyrinSRtoPtRBCQnSubstance RatioPoint 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.