The tissue alkaline phosphatase (ALP) test measures the amount and activity of the ALP enzyme in a small sample of tissue, usually taken from the liver, bone, or another organ during a biopsy. Doctors use this test to help identify liver problems such as hepatitis, cirrhosis, or blocked bile ducts, to detect bone conditions like Paget's disease or osteomalacia, and to determine which organ is affected when blood test results are unclear. The biopsy is performed under local anesthesia, so discomfort is minimal, though the site may feel sore for a few days. Results typically arrive within 3 to 7 days, and your doctor will explain what they mean, along with any rare risks such as bleeding or infection.
This test measures the amount and activity of the alkaline phosphatase enzyme in a tissue sample to help diagnose conditions affecting the bones, liver, or other organs.
{"Measures alkaline phosphatase enzyme activity in tissue samples","Helps diagnose liver disease, bone disorders, or certain cancers","Tissue sample is usually obtained through biopsy","Results are compared with normal tissue values","Abnormal levels may indicate disease or damage to specific organs"}
Key facts at a glance
- LOINC
- 29639-2
- Short code
- ALP-tissue
- Synonyms
- ALP Tiss-cCnt
- Category
- chemistry
- Sample
- serum
- Container
- SST (Serum Separator Tube) gold-top vacutainer, 5-10 mL draw
- Units
- not specified
- Ref low
- 44
- Ref high
- 147
- Critical range
- — – 5 not specified
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Spectrophotometric assay using p-nitrophenyl phosphate (PNPP) as substrate at optimized pH, measuring absorbance at 405 nm
- CPT
- 84075
- SNOMED
- 271544004
- Specimen volume
- Minimum 0.5 mL serum, preferred 1 mL
- Stability
- Room temperature: 7 days; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days. Avoid repeated freeze-thaw cycles
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 40
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The tissue alkaline phosphatase test measures the amount and activity of alkaline phosphatase (ALP) enzyme in a tissue sample. Alkaline phosphatase is an enzyme found in various tissues throughout the body, particularly in the liver, bones, intestines, and kidneys. When a tissue sample is examined, elevated or reduced ALP levels can help doctors identify abnormalities in specific organs.
How is the test performed?
A small tissue sample is collected through a biopsy procedure, where a doctor removes a tiny piece of tissue from the suspected area (such as the liver, bone, or other organ). The sample is then sent to a laboratory where technicians measure the alkaline phosphatase enzyme activity or mass. The procedure is usually done under local anesthesia to minimize discomfort.
Why might I need this test?
Your doctor may order this test if you have symptoms suggesting problems with your liver, bones, or other organs. It can help distinguish between different types of liver diseases, detect bone disorders like Paget's disease or osteomalacia, identify certain cancers that produce ALP, or determine the cause of unexplained pain or dysfunction in specific organs.
What do the results mean?
Results are interpreted based on the type of tissue examined and compared to normal reference values for that specific tissue. Elevated ALP in liver tissue may indicate hepatitis, cirrhosis, or bile duct obstruction. High ALP in bone tissue may suggest bone diseases or tumors. Your doctor will explain what your specific results mean in the context of your overall health and other test findings.
Reference range
Not established (method- and tissue-dependent)not specified
No special preparation; tissue obtained by biopsy or surgical excision per protocol
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The tissue alkaline phosphatase test is clinically significant for diagnosing and monitoring various conditions. In liver diseases, it helps identify cholestasis (bile flow obstruction), hepatitis, and liver tumors. In bone disorders, elevated ALP indicates increased bone turnover activity, seen in conditions like Paget's disease, osteomalacia, or bone metastases. The test can also help differentiate between liver and bone causes of elevated ALP in blood tests, providing more precise diagnostic information.
Frequently asked questions
Is the tissue biopsy painful?
How long does it take to get results?
Are there any risks associated with this test?
Do I need to fast before this test?
How is this different from a blood alkaline phosphatase test?
Sources
- 1
- 2
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.
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