Effectof dialysis on tissue and serum alkaline phosphatase heat stability

Tissue extracts and serum samples were dialyzed against TRIS buffer and the heat stability of the alkaline phosphatase (AP) was examined before and after dialysis for various periods of time. The effect of adding a mixture of ions or heat inactivated polled serum (HIS) to the dialyzed samples was also investigated. Dialysis of tissue extracts or of serum resulted in an increase in the mean AP heat stability. Addition of the ion mixture to dialyzed bone or liver extracts decreased the AP heat stability. Addition of HIS to these extracts decreased the AP heat stability of dialyzed bone extract but had little effect on dialyzed liver extract. These results are discussed.