Serum Alkaline Phosphatase

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Test

When this test is required

ALP is generally part of a routine laboratory test profiles called liver function tests or bone profile. It is usually requested with several other tests if a patient has symptoms of a liver or bone disorder.

What the Test Detects

Alkaline phosphatase is an enzyme found in high amounts in bone and liver. Smaller amounts of ALP are found in the placenta of women who are pregnant, and in the intestines. Each of these body parts makes different forms of ALP. The different forms are called isoenzymes.See MoreSee Less

Preparation for the Test

Fasting is preferred but not essential for this test. Eating a meal can increase the ALP level slightly for a few hours in some people. It is usually better to do the test after fasting overnight. In this case, only water is permitted.

Sample Requirements

A blood sample is taken by needle from a vein in the arm

Additional Notes

Pregnancy can increase ALP levels. Children have higher ALP levels because their bones are growing, and ALP is often very high during ‘growth spurts’ that occurs at different ages in males and females. Temporary elevations of ALP are also seen with healing fractures. Transient benign increases in ALP may also be seen in young infants.Eating a meal can increase the ALP level slightly for a few hours in some people. Ideally the test should be done after fasting overnight. Some drugs may increase ALP levels, especially antibiotics, antihistamines and some of the drugs used to treat psychiatric problems or epilepsy but significant increases are rare.

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