Aldolase
What it measures, and what changes the number.
Aldolase is an enzyme involved in breaking down glucose for energy. It is found in many tissues but is especially abundant in skeletal muscle, and the test measures its activity in serum.
It is usually ordered with CK, the main marker of muscle enzyme release, and often with AST, ALT and sometimes CK-MB, since these enzymes also come from muscle and help show whether a change reflects muscle or liver.
Red blood cells contain aldolase, so a hemolyzed sample (where cells broke during collection or handling) can raise the result, and serum should be separated promptly. Strenuous exercise before the draw can also affect it. Results are reported as enzyme activity, which depends on the assay and temperature used, so values from different labs are not directly comparable. Labs may print it as Aldolasa.