ASSESSMENT OF BUFFERED FORMALIN EFFECT ON ALKALINE PHOSPHATASE ACTIVITY BY MEANS OF ELECTROCHEMICAL METHOD

Aim. To assess the effect of formalin on the activity of alkaline phosphatase in vitro using electrochemical method. Materials and methods. The method based on assessment of alkaline phosphatase activity by its substrate decay products (1-naphthyl phosphate) possessing electrochemical activity was developed. Alkaline phosphatase solution samples were mixed with buffered formalin (10% concentration) in the ratio of 50:50 and stored during 10–240 minutes at the room temperature. Alkaline phosphatase samples free of formalin served as the control. Then, chronoamperometric measurement of enzyme activity after addition of substrate (1-naphthyl phosphate) was performed. Results. It was established that alkaline phosphatase activity is significantly reduced already in 2 hours after its contact with buffered formalin. Conclusion. It is recommended to determine AP activity in nonfixed biological tissues or in 10% neutral formalin fixed tissues for not more than two hours.