Objective: Alkaline phosphatases are glycoprotein structured metalophosphatases with several defined functions. The high concentrations of ALP are found in bone, liver, intestine, and the placenta and ALP serum levels increases in the pathology of these tissues. To understand which tissue caused the ALP increase specific tissue isoenzymes of ALP must be defined. Plasma total ALP consists isoenzymes of bone and liver in healthy people. The aim of this study was; to compare the heat inactivation and agarose gel electrophoresis methods in cirrhosis patients.

Materials and Methods: Values of ALP liver isoenzyme obtained by Agarose gel electrophoresis method (Gel LALP) and heat inactivation method (Heat LALP) were compared with each other either as U/L value or as a percentage of total ALP value in 50 control cases and 50 cirrhosis patients, and the results were evaluated.

Results: Heat LALP values (U/L) were 25.08±7.75 for control group, 37.00±14.58 for patient group. Gel LALP values were 39.24±15.67 for control group, 51.83±21.18 for patient group. Difference between mean values were found to be statistically significant (p<0.05). Heat LALP values (percentage for activity) were 38.93±7.83 for control group, 40.56±9.38 for patient group. Gel LALP values were 59.81±14.20 for control group, 58.19±16.80 for patient group. Difference between mean values were found to be statistically significant (p<0.05).

Conclusion: As a result, heat inactivation method performed at 56ºC' for 10 minutes was found not to be sensitive enough in determination of isoenzymes than agarose gel electrophoresis method.