BACTERIA. MEDIA 



37 



BARIUM 



milk, place measured volumes in flasks 

 or tubes and autoclave 15 lbs., 15 min. 

 Tellurite (for C. diphtheriae). Melt 

 infusion a^ar, or 0.2% dextrose agar, 

 and cool to 50°C. To each 10 cc. add 

 1 cc. citrated, or defibrinated, blood 

 + 1 cc. sterile 2% aq. potassium tellu- 

 rite, mix and pour into Petri dishes. 



Bismuth sulfite agar (Wilson and 

 Blair for E. typhosa) . Mix 20 gm. agar, 

 5 gm. beef extract and 10 gm. peptone 

 in sufficient hot aq. dest. to make 

 1000 cc. Dissolve by autoclaving 15 

 min. Store in refrigerator. (A). Dis- 

 solve 6 gms. bismuth ammonium citrate 

 scales in 50 cc. boiling aq. dest. (1), 20 

 gm. anhydrous sodium sulfite in 100 cc. 

 boiling aq. dest. (2), and 10 gms. dex- 

 trose in 50 cc. boiling aq. dest. (3). 

 Mix 1 and 2, boil and add 10 gms. an- 

 hydrous disodium phosphate while 

 boiling. Cool and add 3. Add water 

 to restore lost weight. Store in closely 

 stoppered pyrex container in dark at 

 room temperature (B). Dissolve 1 gm. 

 ferric citrate in 100 cc. aq. dest. using 

 heat and add 12.5 cc. 1% aq. brilliant 

 green. Store likewise in pyrex vessel 

 in dark. With 1000 cc. hot (A) thor- 

 oughly mix 200 cc. (B) and 45 cc. (C). 

 Immediately pour into porous-top petri 

 dishes each 15-20 cc. After 2 hrs. at 

 room temperature store in refrigerator 

 and use within 4 days. 



Chocolate agar (for Neisseria). 

 Grind strips lean meat of 5-6 beef 

 hearts. To each 500 gm. add 1000 cc. 

 tap water, infuse in refrigerator over 

 night, strain and press through course 

 gauze. Add 10 gm. proteose peptone 

 No. 3 (Difco) per liter, heat to 50''C. 

 1 hr. and boil 10 min. Strain through 

 gauze, dissolve 5 gm. sodium chloride 

 per liter and titrate to pH 7.6. Boil 

 lightly 10 min. pour off measured quan- 

 tities in flasks, autoclave 15 lbs., 15 

 min. Cool to 60°C., add 5% human or 

 horse blood, heat slowly on water bath 

 to 80-85°C. rotating to get even mix- 

 ture. Cool to 55°C. and plate. 



Bacterial Pigments. These cannot be meas- 

 ured microscopically but a method has 

 been devised for doing so with spectro- 

 photometer and photoelectric colorim- 

 eter (Stahly, G. L., Sesler, C. L. and 

 Erode, W. R., J. Bact., 1942, 43, 

 149-154). 



Bacterial Polysaccharides. Solutions of 

 reduced bases and leuco bases of penta- 

 and hexa-methyl triamino-triphenyl- 

 methane and tetramethyl diamino- 

 triphenylmethane and certain other 

 triphenylmethanes react with staphylo- 

 coccal polysaccharides and may be 

 useful in their detection (Chapman, 



G. H. and Lieb, C. W., Stain Techn., 

 1937, 12, 15-20). 



Bacteriostatic Titration of Dyes. (Reed, 

 M. V. and Genung, E. F., StainT'echn., 

 1934, 9, 117-128). 



Bacterium Monocytogenes. Intravenous 

 injections of this organism in rabbits 

 produce a marked increase in the num- 

 ber of circulating monocytes and there- 

 fore provide an important experimental 

 method (Murray, E. G. D.,Webb,R.H. 

 and Swan, M. B. R., J. Path, and Bact., 

 1926, 29, 407-439). 



Bacterium Tularense in sections. Add 10 

 cc. sat. aq. nile blue sulphate and 6 cc. 

 l%aq. safranin to60 cc.aq. dest. Stain 

 sections over night. Wash quickly, 

 dehydrate in alcohols, clear in xylol 

 and mount (Foshay, L., J. Lab. & Clin. 

 Med., 1931, 17, 193-195). 



Balsam for mounting sections is usually 

 satisfactory as purchased. To make, 

 rnix equal parts dry balsam and sodium 

 bicarbonate and grind in mortar. Add 

 sufficient xylol to make clear solution. 

 After few days filter and heat gently 

 (avoiding flame) to bring to suitable 

 consistency. The best mounting me- 

 dium when neutrality is essential is 

 Clarite or the cedar oil used for oil 

 immersion objectives. The latter sets 

 more slowly than balsam and it is ordi- 

 narily not necessary to employ it. See 

 Mounting Media. 



Barber and Eomp thick film for malaria 

 Plasmodia (Barber, M. A. and Komp, 

 W. H. W., Pub. Health Rep., 1929, 44, 

 2330) is described by Craig, p. 290-291 

 as the most used and satisfactory of the 

 thick film techniques. His account of 

 the method abbreviated: Place large 

 drop blood on clean slide and smear with 

 needle over area about half size of that 

 usually covered by a thin blood smear. 

 Dry in incubator at 37°C., 1-1| hrs. 

 Stain in 1 part good Giemsa and 6 parts 

 neutral or slightly alkaline aq. dest., 

 about 30 min. Partly decolorize in 

 aq. dest. 5 min. (If films have back- 

 ground deep blue and leucocytes almost 

 black they may be worthless; but leav- 

 ing in aq. dest. longer may help). 

 Drain thoroughly, dry and examine. 



Barium, spectrographic analysis of, in retina 

 (Scott, G. H. and Canaga, B., Jr., Proc. 

 Soc. Exp. Biol. & Med., 1940, 44, 555- 

 556). Barium chloride and formalin are 

 advised as fixative for Bile Components. 

 Barium sulphate emulsion injections are 

 recommended by Woollard, H. H. and 

 Weddell, G., J. Anat., 1934-35, 69, 25-37 

 to demonstrate arterial vascular 

 patterns. The emulsion should be of 

 such consistency that it cannot easily be 

 forced beyond the small arterioles by a 

 pressure of 1 .5 atmospheres . Fix tissues 



