Sign in →

Test Code APTIS / ALKI-M Alkaline Phosphatase, Total and Isoenzymes, Serum

Additional Codes

Software Test Code

Reporting Name

Alkaline Phosphatase, Tot and Iso,S

Useful For

Diagnosis and treatment of liver, bone, intestinal, and parathyroid diseases


Determining the tissue source of increased alkaline phosphatase (ALP) activity in serum


Differentiating between liver and bone sources of elevated ALP

Profile Information

Test ID Reporting Name Available Separately Always Performed
ALP Alkaline Phosphatase, S Yes Yes
ALKE Alkaline Phosphatase Isoenzymes, S No Yes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type


Necessary Information

Patient's age and sex are required.

Specimen Required

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL, divided

Collection Instructions: Centrifuge and aliquot serum into 2 tubes, each containing 0.5 mL

Specimen Minimum Volume

0.5 mL divided into 2 tubes each containing 0.25 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 14 days
  Ambient  7 days
  Refrigerated  7 days

Reference Values



0-14 days: 83-248 U/L

15 days-<1 year: 122-469 U/L

1-<10 years: 142-335 U/L

10-<13 years: 129-417 U/L

13-<15 years: 116-468 U/L

15-<17 years: 82-331 U/L

17-<19 years: 55-149 U/L

≥19 years: 40-129 U/L


0-14 days: 83-248 U/L

15 days-<1 year: 122-469 U/L

1-<10 years: 142-335 U/L

10-<13 years: 129-417 U/L

13-<15 years: 57-254 U/L

15-<17 years: 50-117 U/L

≥17 years: 35-104 U/L



Liver 1%

0-6 years: 5.1-49.0%

7-9 years: 3.0-45.0%

10-13 years: 2.9-46.3%

14-15 years: 7.8-48.9%

16-18 years: 14.9-50.5%

≥19 years: 27.8-76.3%

Liver 1

0-6 years: 7.0-112.7 IU/L

7-9 years: 7.4-109.1 IU/L

10-13 years: 7.8-87.6 IU/L

14-15 years: 10.3-75.6 IU/L

16-18 years: 13.7-78.5 IU/L

≥19 years: 16.2-70.2 IU/L

Liver 2%

0-6 years: 2.9-13.7%

7-9 years: 3.7-12.5%

10-13 years: 2.9-22.3%

14-15 years: 2.2-19.8%

16-18 years: 1.9-12.5%

≥19 years: 0.0-8.0%

Liver 2

0-6 years: 3.0-41.5 IU/L

7-9 years: 4.0-35.6 IU/L

10-13 years: 3.3-37.8 IU/L

14-15 years: 2.2-32.1 IU/L

16-18 years: 1.4-19.7 IU/L

≥19 years: 0.0-5.8 IU/L

Bone %

0-6 years: 41.5-82.7%

7-9 years: 39.9-85.8%

10-13 years: 31.8-91.1%

14-15 years: 30.6-85.4%

16-18 years: 38.9-72.6%

≥19 years: 19.1-67.7%


0-6 years: 43.5-208.1 IU/L

7-9 years: 41.0-258.3 IU/L

10-13 years: 39.4-346.1 IU/L

14-15 years: 36.4-320.5 IU/L

16-18 years: 32.7-214.6 IU/L

≥19 years: 12.1-42.7 IU/L

Intestine %

0-6 years: 0.0-18.4%

7-9 years: 0.0-18.3%

10-13 years: 0.0-11.8%

14-15 years: 0.0-8.2%

16-18 years: 0.0-8.7%

≥19 years: 0.0-20.6%


0-6 years: 0.0-37.7 IU/L

7-9 years: 0.0-45.6 IU/L

10-13 years: 0.0-40.0 IU/L

14-15 years: 0.0-26.4 IU/L

16-18 years: 0.0-12.7 IU/L

≥19 years: 0.0-11.0 IU/L


Not present

Day(s) Performed

Monday through Friday

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information



LOINC Code Information

Test ID Test Order Name Order LOINC Value
ALKI Alkaline Phosphatase, Tot and Iso,S 24332-9


Result ID Test Result Name Result LOINC Value
ALP Alkaline Phosphatase, S 6768-6
89503 Alkaline Phosphatase Isoenzymes, S 49243-9
45488 Liver 1 % 15348-6
57034 Liver 1 13874-3
45489 Liver 2 % 15349-4
57035 Liver 2 13875-0
45490 Bone % 15013-6
57036 Bone 1777-2
45491 Intestine % 15014-4
57037 Intestine 1778-0
29324 Placental 40793-2

Clinical Information

Alkaline phosphatase (ALP) is present in a number of tissues including liver, bone, intestine, and placenta. The activity of ALP found in serum is a composite of isoenzymes from those sites and, in some circumstances, placental or Regan isoenzymes. Serum ALP is of interest in the diagnosis of 2 main groups of conditions: hepatobiliary disease and bone disease associated with increased osteoblastic activity.


A rise in ALP activity occurs with all forms of cholestasis, particularly with obstructive jaundice. The response of the liver to any form of biliary tree obstruction is to synthesize more ALP. The main site of new enzyme synthesis is the hepatocytes adjacent to the biliary canaliculi.


ALP is also elevated in disorders of the skeletal system that involve osteoblast hyperactivity and bone remodeling, such as Paget disease, rickets, osteomalacia, fractures, and malignant tumors.


Moderate elevation of ALP may be seen in other disorders such as Hodgkin disease, congestive heart failure, ulcerative colitis, regional enteritis, and intra-abdominal bacterial infections.


No significant cautionary statements

Method Description

Total Alkaline Phosphatase:

In the presence of magnesium and zinc ions, p-nitrophenyl phosphate is cleaved by phosphatases into phosphate and p-nitrophenol. The p-nitrophenol released is directly proportional to the catalytic alkaline phosphatase (ALP) activity. It is determined by measuring the increase in absorbance.(Package insert: Alkaline Phosphatase reagent. Roche Diagnostics; 02/2012)


ALP Isoenzymes:

Serum samples are electrophoresed through alkaline buffered (pH 9.1) agarose gels. Almost all ALP isoenzymes can be separated by electrophoresis according to their charge difference. However, because the electrophoretic mobilities of the liver and bone isoenzymes are quite similar, a modification is required for separation. The Sebia system utilizes differences between liver and bone isoenzyme sialation to achieve separation. Each sample is applied to the agarose gel in duplicate. One sample is passed through wheat germ lectin (wheat germ agglutin:WGA) and is deposited anodally from the point of sample application. The bone isoenzyme, which is rich in sialic acids, reacts with WGA and precipitates adjacent to the lectin application point. The separated isoenzymes are visualized using a specific chromogenic substrate, 5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium in aminomethyl propanol (AMP) buffer, pH 10.0. The dried gels are read on a densitometer for the quantification of tissue isoforms.(Package insert: Sebia Hydragel 7 and 15 ISO-PAL. Sebia; 01/2017)

Report Available

2 to 5 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Method Name

ALP: Colorimetric

ALKE: Electrophoresis

Secondary ID