464 BACTERIOLOGICAL ANALYSES 



Apparatus Required: 



Two hard nail brushes. 



Liquid soap. 



Sterile water in aspirator jar with delivery nozzle controlled 

 by a spring clip. 



Sterile oyster knives. 



Sterile glass dish, with cover, sufficiently large to accommodate 

 ten oysters. 



Sterile forceps. 



Sterile scissors. 



Sterile towels or large gauze pads. 



Sterile graduated cylinders 1000 c.c. capacity, with either the 

 lid or the bottom of a sterile Petri dish inverted over the 

 open mouth as a cover. 



Glass rods. 



Corrosive sublimate solution, i per mille. 



Bile salt broth tubes. 



Litmus milk tubes. 



Surface plates of nutrose agar. 



Case of sterile pipettes, i c.c. (in tenths of a c.c.) 



Case of sterile pipettes, 10 c.c. (in tenths of a c.c.) 



Case of sterile glass capsules. 



Erlenmeyer flasks, 250 c.c. capacity. 



Double strength bile salt broth. 



METHOD. 



1. Thoroughly clean the outside of the oyster shells 

 by scrubbing each in turn with liquid soap and nail 

 brush under a tap of running water. Then, holding 

 an oyster shell in a pair of sterile forceps wash every 

 part of the outside of the shell with a stream of sterile 

 water running from an aspirator jar; deposit the oyster 

 inside the sterile glass dish. Repeat the process with 

 each of the remaining oysters. 



2. Before proceeding further, cleanse the hands 

 thoroughly with clean nail brush, soap and water, 

 then plunge them in lysol 2 per cent, solution, and 

 finally in sterile water. 



3. Spread a sterile towel on the bench. 



4. Remove one of the oysters from the sterile glass 

 dish and place it, resting on its convex shell, on the 



