Introduction. As to the nature of the antitrypsin of serum, a great deal has been written, and even at the present day various views are held in regard to it. In our laboratory several tests were performed in order to see how it can be inactivated and which part of the serum exerts the antitryptic action.
Preparation and Method of Our Tests. In our experiments von Bergmann's casein method was modified a little to make the reaction finer. Namely:
Solution of casein: 0.5 gram of casein was dissolved in 50 cc. of N/10 NaOH solution and the solution was warmed a while. Then the solution was neutralized with N/10 muriatic acid and finally diluted to 500 cc. with normal salt solution. This solution of casein in our case is, therefore, less concentrated than that usually employed; i.e., it is of 0.1 per cent instead of 0.2 per cent.