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Chromosomal Analysis by Interphase Fluorescence In Situ Hybridization (FISH) on Peripheral Blood Cells

Published: August 9, 2026Updated: August 16, 2026

This test examines chromosomes in cells from your blood using a fluorescent technique to detect genetic abnormalities without requiring cell division.

Quick summary

["Helps identify potential genetic changes in your blood cells that may affect health or guide treatment decisions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
55193-7
Short code
Chrom analy interphase CVS FISH-Imp
Synonyms
Chrom analy interphase CVS FISH-Imp
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
fish
CPT
86038
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

Why This Test Is Done

Doctors may order this test to investigate suspected genetic disorders, monitor conditions like cancer, or evaluate risks for inherited genetic conditions. It’s particularly useful when other tests suggest chromosomal issues but don’t provide clear answers.

How the Test Works

A small blood sample is taken, and cells are placed in a lab setting to stop them from dividing. Fluorescent probes are then applied to specific chromosomes to highlight any genetic differences, such as missing, extra, or rearranged pieces of DNA.

Sample Preparation

The blood sample is processed to isolate cells in their non-dividing (interphase) state. This method avoids artifacts that can occur during cell division, ensuring more accurate detection of chromosomal abnormalities.

What to Expect Before the Test

No special preparation is needed beyond the standard blood draw. You may be asked to fast or avoid certain medications, but this depends on your doctor’s instructions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Interphase FISH Chromosomal Analysis

Frequently asked questions

How long does it take to get results?
Results are typically available within 1–2 weeks, depending on lab processing and any additional testing required.
What does a positive result mean?
A positive result indicates the presence of chromosomal abnormalities that may relate to a genetic condition, cancer, or other health concerns. Your doctor will discuss the findings in detail and explain next steps.
Can this test be done on other body fluids?
No, this test specifically uses blood cells in their interphase state, so it’s not applicable to other fluids like urine or cerebrospinal fluid.
  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 16, 2026. · Read our editorial policy