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.

LOINCActiveOrder

LOINC Code 90991-1: Protein electrophoresis and M protein isotype panel

Name: LOINC Code 90991-1: Protein electrophoresis and M protein isotype panel
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:20.875Z

90991-1 is a LOINC code used to identify Protein electrophoresis and M protein isotype panel 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 Protein electrophoresis & monoclonal protein isotype panel. It is commonly used with the system or sample type Ser/Plas.

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 Protein electrophoresis & monoclonal protein isotype panel. It is commonly used with the system or sample type Ser/Plas.

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: Order
Panel type: Panel

What it does not mean

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

Key facts

Protein electrophoresis and M protein isotype panel - Serum or Plasma
Protein electrophoresis & monoclonal protein isotype panel
This panel contains results for serum protein electrophoresis testing as well as monoclonal protein isotype by MALDI-TOF; it does not include free light chain analysis. This panel is used for diagnosing monoclonal gammopathies such as multiple myeloma and monoclonal gammopathy of unknown significance (MGUS).
Chemistry; MPQU; Pan; PANEL.CHEMISTRY; Panl; Pl; Plasma; Plsm; Pnl; Point in time; PR; Prot; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SPEP; SR

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

Protein electrophoresis and M protein isotype panelProtein electrophoresis and M protein isotype panel - Serum or PlasmaMPQU SerPlProtein electrophoresis & monoclonal protein isotype panelPANEL.CHEMProtein Electrophoresis and M Protein Isotype Panel, Blood-

Frequently asked questions

Code details

Code90991-1

SystemLOINC

Display nameProtein electrophoresis and M protein isotype panel

DescriptionProtein electrophoresis & monoclonal protein isotype panel

Short nameMPQU SerPl

ComponentProtein electrophoresis & monoclonal protein isotype panel

Property-

TimingPt

System (specimen)Ser/Plas

Scale-

ClassPANEL.CHEM

StatusACTIVE

Order/ObservationOrder

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.65

Last changed2.75

Consumer names

Protein Electrophoresis and M Protein Isotype Panel, Blood

Part names

Protein electrophoresis & monoclonal protein isotype panel-PtSer/PlasProtein electrophoresis and M protein isotype panelPoint in time (spot)Serum or Plasma

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.