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Bcrabl1b2a2bldtql

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

This test detects the BCR-ABL1 fusion gene, commonly associated with chronic myeloid leukemia (CML) and some acute lymphoblastic leukemias.

Quick summary

{"Detects a genetic abnormality called the Philadelphia chromosome","Used to diagnose and monitor chronic myeloid leukemia (CML)","Performed on a whole blood sample","Results help guide treatment decisions","Regular testing tracks how well treatment is working"}

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

Key facts at a glance

LOINC
49490-6
Short code
BCRABL1B2A2
Synonyms
BCR-ABL1 b2a2 Bld/T Ql
Category
chemistry
Sample
whole-blood
Container
EDTA (purple-top) or ACD (yellow-top) anticoagulated whole blood tube for peripheral blood; sterile container without fixative for tissue specimens (bone marrow or other).
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
molgen
CPT
81206
SNOMED
427357008
Specimen volume
3-5 mL whole blood for peripheral blood; 1-2 mL bone marrow aspirate in EDTA; minimum 0.5 mL for tissue specimens.
Stability
Whole blood: Room temperature 24 hours; refrigerated (2-8°C) up to 72 hours; frozen at -20°C to -80°C for extended storage. RNA extraction should be performed promptly to prevent degradation. Avoid repeated freeze-thaw cycles.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
48–168 hours
Order
routine

What is this test?

The BCR-ABL1 b2a2 fusion protein test is a molecular genetics test that looks for a specific genetic abnormality in your blood or tissue. This abnormality occurs when parts of two different chromosomes (chromosome 9 and chromosome 22) swap places, creating a fusion gene called BCR-ABL1. This is also known as the Philadelphia chromosome.

Why do I need this test?

Your doctor may order this test if they suspect you have chronic myeloid leukemia (CML) or certain types of acute lymphoblastic leukemia (ALL). The test helps: 1) Confirm a diagnosis, 2) Determine the specific type of leukemia, 3) Guide treatment decisions, and 4) Monitor how well treatment is working over time.

How is the test done?

A healthcare professional will collect a blood sample from a vein in your arm. The sample is then sent to a laboratory where specialized technicians look for the BCR-ABL1 fusion gene using molecular genetics techniques. You may feel a brief sting when the needle is inserted, and there may be some bruising afterward, but the procedure is generally quick and safe.

What do the results mean?

Results are reported as 'Detected' or 'Not Detected.' If the BCR-ABL1 fusion gene is detected, it suggests you have a leukemia associated with this genetic abnormality. Your doctor will interpret these results along with other tests and your overall health condition to determine the best treatment plan.

Reference range

Negative: BCR-ABL1 b2a2 fusion transcript not detected. Positive results are typically reported as the ratio of BCR-ABL1 transcripts to ABL1 control transcripts (IS) or as a percentage.N/A

Specimen: whole-blood

No fasting required. Patient should be informed about the genetic nature of the test. Genetic counseling may be recommended for newly diagnosed patients and their family members when considering implications of disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is this test painful?
The test involves drawing blood, which may cause brief discomfort similar to a pinch. Most people tolerate it well with minimal pain.
How long does it take to get results?
Molecular genetics tests typically take longer than routine blood tests. Results may take anywhere from several days to a couple of weeks, depending on the laboratory.
Do I need to fast before this test?
No, fasting is not required for this test. You can eat and drink normally before having your blood drawn.
Can this test tell me if I have cancer?
This test detects a genetic abnormality commonly associated with certain types of leukemia. A positive result suggests the presence of this abnormality, but your doctor will combine this information with other tests, symptoms, and clinical findings to make a complete diagnosis.
How often will I need this test?
If you are being treated for CML or related leukemia, your doctor will regularly order this test to monitor your response to treatment. The frequency varies depending on your situation—initially more often, then less frequently once stable.
  1. 1
    American Cancer Society - Chronic Myeloid LeukemiaSource
  2. 2
    National Cancer Institute - Chronic Myeloid Leukemia TreatmentSource
  3. 3
    Mayo Clinic - Chronic Myeloid LeukemiaSource

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