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Test ID: ADA    
Adenosine Deaminase, Blood

Method Description Describes how the test is performed and provides a method-specific reference

The adenosine deaminase (ADA) assay is based on the enzymatic deamination of adenosine to inosine. Inosine is converted to hypoxanthine by purine nucleoside phosphorylase (PNP). Hypoxanthine is then converted to uric acid and hydrogen peroxide (H2O2) by xanthine oxidase (XOD). H2O2 is further reacted with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (EHSPT) and 4-aminoantipyrine (4-AA) in the presence of peroxidase (POD) to generate quinone dye which is monitored in a kinetic manner. The entire enzymatic reaction scheme is shown below.





adenosine + H2O


inosine + NH3




inosine + Pi


hypoxanthine + ribose-1-phosphate




hypoxanthine + 2H2O + 2O2


uric acid + 2H2O2




4H2O2 + 4-AA + EHSPT


4H2O + quinone dye (lamda max 556 nm)


One unit of ADA is defined as the amount of ADA that generates 1 micromole of inosine from adenosine per minute at 37 degrees C.(Beutler E: Red cell metabolism. In A Manual of Biochemical Methods. Second edition. Grune and Stratton, 1984, pp 99-100)

Supplemental Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.

Monday through Friday

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

10 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

10 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week

Performing Laboratory Location The location of the laboratory that performs the test