Skip to content

Scallop-Specific IgG, Qualitative (RAST) — Deprecated

Published: August 9, 2026Updated: August 17, 2026

A legacy qualitative test for scallop-specific IgG antibodies, used to assess immune exposure to scallop. It is deprecated and does not by itself diagnose food allergy.

Quick summary

["A positive result shows exposure to scallop but does not necessarily mean you have a clinical food allergy."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
21516-0
Short code
Deprecated Scallop IgG RAST Ql
Synonyms
Deprecated Scallop IgG RAST Ql
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84484
SNOMED
302774002
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This is a qualitative laboratory test designed to detect IgG antibodies directed against scallop proteins. It is a legacy, deprecated test and may not be available from all laboratories.

Why might I need this test?

It may have been used to assess whether your immune system has reacted to scallop after dietary exposure or symptoms. Results are best considered alongside your medical history and other allergy evaluations.

How is the test performed?

A laboratory sample, usually blood, is tested for scallop-specific IgG antibodies. A qualitative report generally indicates whether the antibodies were detected or not detected.

How do I prepare for the test?

No special preparation is usually required for this test. Follow the laboratory or clinician's instructions, particularly if the test is being ordered with other procedures that may require fasting.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Scallop-Specific IgG (RAST)

Frequently asked questions

Does a positive scallop IgG result mean I am allergic to scallop?
No. Scallop-specific IgG can occur after exposure without causing symptoms and is not a reliable stand-alone marker of food allergy.
What symptoms may be related to a scallop allergy?
Possible allergic symptoms include hives, itching, swelling, abdominal symptoms, wheezing, or other reactions after eating scallop. Seek urgent medical care for breathing difficulty, throat swelling, faintness, or a rapidly worsening reaction.
Why is this test considered deprecated?
The test is a legacy option and may no longer be routinely offered. Your clinician can interpret it alongside your history and, when needed, current IgE-based or skin-prick allergy testing.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy