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Alkaline Phosphatase (ALP)

Test ID: A875

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Alkaline phosphatase (ALP) is an enzyme found in several different tissues. Very high ALP levels are associated with cholestatic liver disease, bile duct obstruction, alcoholic hepatitis, and drug-induced liver injury. Moderately high ALP levels are associated with other liver complications, heart failure, bacterial infections, and kidney cancer. Low ALP may occur in cases of malnutrition or deficiency in certain vitamins and minerals.



How to order a test


  • ALP

What is Included?

Measurement of alkaline phosphatase levels in a blood sample by the para-nitrophenyl phosphate methodology.

Turnaround Time

1 – 3 business days
The turnaround time is not guaranteed. The average turnaround time is 1 – 3 business days from the date that the sample arrives at the laboratory. Shipping time for the sample is not included. Additional time is required if the case requires confirmatory or reflex testing, or if the sample is insufficient, or if a recollection is required.

Related Documents

Special Instructions

Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient’s course of therapy.


Preparation Before Specimen Collection

Blood sample should be collected in a fasting state (10-12 hours).

Specimen Type



50 μL in a microtainer


Microtainer (regular blood tube)

Collection Method

This test requires a blood sample from a finger prick. All supplies for sample collection are provided in the kit.

  1. First wash and dry hands. Warm hands aid in blood collection.
  2. Clean the finger prick site with the alcohol swab and allow to air dry.
  3. Use the provided lancet to puncture the skin in one quick, continuous and deliberate stroke.
  4. Wipe away the first drop of blood.
  5. Massage hand and finger to increase blood flow to the puncture site. Angle arm and hand downwards to facilitate blood collection on the fingertip.
  6. Drip blood into the microtainer tube.
  7. Dispose of all sharps safely and return sample to the laboratory in the provided prepaid return shipping envelope.

NOTES: Avoid squeezing or ‘milking’ the finger excessively. If more blood is required and blood flow stops, perform a second skin puncture on another finger. Do not touch the fingertip.

Specimen Storage

Maintain specimen at temperatures between 2°C and 30°C during storage and transport.

Specimen Stability

Blood samples can be refrigerated or kept at room temperature for up to 7 days.

Causes for Rejection

  • Incorrect or incomplete patient identification
  • Incorrect specimen collection
  • Inappropriate storage and transport conditions
  • Incorrect specimen volume



To measure alkaline phosphatase levels in a blood sample predominantly for the detection of liver disease.

Up to 75% of individuals with cholestatic liver disease have elevated ALP that is at least 4-fold higher than the normal upper limit. High elevations also occur in bile duct obstruction (due to gallbladder inflammation, gallstones, or cancer), infiltrative liver disease, severe alcoholic hepatitis, and drug-induced liver injury. AIDS patients may also have similar ALP elevations, either due to opportunistic infections or tuberculosis complications.

Moderate ALP elevations (up to 4-fold increase) can occur in a variety of situations, including cirrhosis of the liver, chronic and viral hepatitis, congestive heart failure, Hodgkin lymphoma, myeloid metaplasia, kidney cancer, and bacterial infection. Bone disorders that cause excessive bone formation (e.g. Paget’s disease) can also increase ALP levels in the blood.

Lower-than-normal ALP levels are rare, but may occur in cases of malnutrition, or a deficiency in certain vitamins and minerals. Celiac disease is one disorder that can contribute to a malnourished state.


  • This report is not intended for use in medico-legal applications.
  • These results should be interpreted in conjunction with other laboratory and clinical information.
  • Correct specimen collection and handling is required for optimal assay performance.
  • Certain medications (e.g., statins, aspirin, opioids, and some antibiotics), some natural health products, very strenuous recent physical exercise or severe injury to muscle, and recent surgery may affect results.


Para-nitrophenyl phosphate methodology (Alinity c Alkaline Phosphatase assay)

Reference Intervals

Normal alkaline phosphatase levels in serum or plasma are:
0 – 14 days: 90 – 273 U/L
15 days – <1 year: 134 – 518 U/L
1 – <3 years: 156 – 369 U/L
3 – 5 years: 144 – 327 U/L
6 – 10 years: 153 – 367 U/L
11 – 15 years, Males: 113 – 438 U/L
11 – 15 years, Females: 64 – 359 U/L
16 – 21 years, Males: 56 – 167 U/L
16 – 29 years, Females: 44 – 107 U/L
22 – 79 years, Males: 50 – 116 U/L
30 – 79 years, Females: 46 – 122 U/L

These reference ranges were obtained from Rifai N, Horvath AR, & Wittwer C. (2018). Tietz textbook of clinical chemistry and molecular diagnostics (Sixth edition.). St. Louis, Missouri: Elsevier.