Diagnostic Reagents 



BAGTO-THROMBOPLASTIN (B226) 



Bacto-Thromboplastin is stabilized, desiccated rabbit brain substance for use 

 in determining the prothrombin time of bloods from patients with obstructive 

 jaundice, hepatitis, cirrhosis, hepatic neoplasia, biliary fistula, colitis, cholangitis, 

 hemorrhagic disease of the newborn, and other conditions wherein hypopro- 

 thrombinemia is suspected. It is particularly recommended for use in following 

 prothrombin activity in patients on dicoumarol, tromexan or other anticoagulant 

 therapy. It is applicable to the procedures described by Quick,i'2'3 Smith, 

 Warner and Brinkhouse,^ the bedside test of Smith et al.^, the micro-prothrombin 

 test of Kato,® and Kato and Poncher,'' the dilute plasma technique of Campbell, 

 Smith, Roberts and Link,^ Shapiro, Sherwin, Redish and Campbell,^ Shapiro^", 

 and its extensions^i'^^-^^'^* and is recommended for all tests requiring a potent 

 thromboplastin. Bacto-Thromboplastin has given exceptionally good results in 

 the preparation of the Two-Stage Reagent for the quantitative determination of 

 prothrombin concentration as described by Ware and Seegers.^^ 



Quick Prothrombin Time Test^ 

 Reagents: 



1. Bacto-Thromboplastin 



Empty the contents of one ampul Bacto-Thromboplastin into a clean dry 

 test tube. Add 4.0 ml. of 0.85 per cent sodium chloride solution. Mix lightly 

 to suspend and wet all particles. Incubate the mixture in a water bath at 

 45-48°C., for 10 minutes, during which time gently twirl the tube momen- 

 tarily at three-minute intervals to resuspend the solids. Avoid excessive agi- 

 tation as this will yield an unsatisfactory heavy milky extract. 



Place a thin layer of absorbent cotton over the wide end of a clean dry 

 pipette. Insert the covered end into the tube containing the incubated 

 thromboplastin mixture and carefully lower it through the suspension to the 

 bottom of the tube keeping the end of the pipette pressed firmly against 

 the cotton. Withdraw as much extract as possible through the cotton by 

 gentle suction and transfer the filtered extract to a clean container. The 

 filtered extract should be opalescent without particles. Some laboratories 

 may prefer to use the extract without filtration. In such cases it is best to 

 employ a pipette with a wide tip orifice. 



The Thromboplastin Extract should be used within six hours following 

 preparation. Unused portions of the Thromboplastin Extract should be 

 frozen solidly in the freezing compartment of the refrigerator, thawed and 

 reincubated for 5 minutes at 37°C. before being used in the test. Extract 

 properly frozen will retain full potency for at least three months. Repeated 

 thawing and freezing of the extract is not recommended. Accordingly, if the 

 extract is prepared for stock use it should be distributed in amounts of 

 approximately one day's usage or single test dose (0.1 ml.) and then frozen 

 and stored as recommended above. In such cases the amount required for 

 a day's use or one test can then be withdrawn from the freezer, thawed and 

 reincubated as specified. 



2. Bacto-Sodium Oxalate 0.1 Molar or dissolve 1.34 grams of anhydrous re- 

 agent grade sodium oxalate in 100 ml. of distilled water. 



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