DIAGNOSTIC REAGENTS 323 



BAGTO-PROTHROMBIN 2 STAGE (B407) 

 REAGENT 



Bacto-Prothrombin 2 Stage Reagent is a desiccated reaction mixture dried 

 from the frozen state, prepared according to the specifications of Ware and 

 Seegers/ for use in the two-stage procedure for the quantitative determination 

 of prothrombin concentration and Ac globulin. The two-stage prothrombin con- 

 centration determination, as the name implies, is carried out in two steps. The 

 fibrinogen is first removed from the plasma under test by adding thrombin. The 

 clot which forms is defibrinated and the resulting fluid allowed to stand for a 

 short time for destruction of the added thrombin by the antithrombin present in 

 the serum. The second step consists of measuring quantitatively the unaltered 

 prothrombin in the fibrinogen-free plasma. This is accomplished by adding 

 Bacto-Prothrombin 2 Stage Reagent and Bacto-Ac Globulin to the fibrinogen- 

 free plasma to convert the prothrombin to thrombin and subsequently measuring 

 the thrombin activity on a standardized solution of fibrinogen. A thrombin unit 

 is that amount of thrombin which will clot 1 ml. of standardized fibrinogen 

 solution in 15 seconds under conditions imposed by the two-stage analysis. One 

 unit of thrombin is derived from each unit of prothrombin. Therefore, the pro- 

 thrombin unitage is the same as that of the thrombin. Complete details of the 

 two-stage procedure for measuring prothrombin concentration are outlined by 

 Ware and Seegers.^ 



Bacto-Prothrombin 2 Stage Reagent is supplied in vials of 10 ml. which are 

 rehydrated by adding 10 ml. 0.6 per cent sodium chloride solution. Bacto- 

 Prothrombin 2 Stage Reagent as well as the resulting solution should be refrig- 

 e: ated when not in use. 



Bacto-Ac Globulin is also available for use in conjunction with Bacto-Pro- 

 thrombin 2 Stage Reagent in the two-stage procedure for the quantitative deter- 

 mination of prothrombin concentration. 

 lAm. J. Clin. Path., 19:471:1949. 



BAGTO-Ac GLOBULIN (B447) 



Bacto-Ac Globulin is desiccated beef serum dried from the frozen state pre- 

 pared according to the specifications of Ware and Seegers,^ for use as a source of 

 accelerator globulin in the two stage procedure for the quantitative determina- 

 tion of prothrombin. It is recommended for use in conjunction with Bacto-Pro- 

 thrombin 2 Stage Reagent for the total conversion of prothrombin to thrombin. 



Bacto-Ac Globulin is rehydrated by adding 2 ml. sterile distilled water to each 

 vial to give a solution comparable with fresh beef serum. The reconstituted Ac 

 Globulin is further diluted with 0.85 per cent sodium chloride solution to give a 

 final concentration of 1 : 600 as used in the two stage prothrombin concentration 

 test of Ware and Seegers. Bacto-Ac Globulin as well as the solution should be 

 stored in the refrigerator at 2-6° C. 



Bacto-Ac Globulin is supplied in 2 ml. vials in packages of 6. 



lAm. J. Clin. Path., 19:471:1949. 



