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 102777-0: Onion IgG RAST (S) [Presence]

Name: LOINC Code 102777-0: Onion IgG RAST (S) [Presence]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:17.902Z

102777-0 is a LOINC code used to identify Onion IgG RAST (S) [Presence] 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 Allium cepa Ab.IgG. 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 Allium cepa Ab.IgG. 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
Method: RAST

What it does not mean

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

Key facts

Onion IgG Ab [Presence] in Serum by Radioallergosorbent test (RAST)
Allium cepa Ab.IgG
ABS; Aby; Allergen; Allergens; ALLERGY TESTING; Allium salota Dostál; Antby; Anti; Antibodies; Antibody; Autoantibodies; Autoantibody; f048; f48; Immune globulin G; Immunoglobulin G; Onion; Point in time; PR; Radioallergosorbent test; Random; Serum; SmQn; 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

Onion IgG RAST (S) [Presence]Onion IgG Ab [Presence] in Serum by Radioallergosorbent test (RAST)Onion IgG RASTAllium cepa Ab.IgGALLERGYOnion IgG antibodyPrThr

Frequently asked questions

Code details

Code102777-0

SystemLOINC

Display nameOnion IgG RAST (S) [Presence]

DescriptionAllium cepa Ab.IgG

Short nameOnion IgG RAST

ComponentAllium cepa Ab.IgG

PropertyPrThr

TimingPt

System (specimen)Ser

ScaleSemiQn

MethodRAST

ClassALLERGY

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.75

Last changed2.75

Consumer names

Onion IgG antibody

Part names

Allium cepa Ab.IgGPrThrPtSerSemiQnRASTOnion (Allium cepa) IgGPresence or ThresholdPoint in time (spot)SerumRadioallergosorbent test (RAST)

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.