Page:The Indian Journal of Medical Research, Volume 9.djvu/112

 BACTERIOLOGICAL AND LABORATORY TECHNIQUE

Section II. BY Lieut.-Colonel W. F. HARVEY, M.A., M.B., D.P.H., C.I.E., I.M.S., Direntor, Central Research Instilule. Kasaiili. [Received for publication, January 7, 1921.]

Media. 1. MEDIA. PREPARATION OF AGAR : Ml'l FIBRE AGAR : Ml'll. — (1) Prepare: — Fibre agar 1 ; glacial acetic acid 0"05 ; water 2. (2) Allow the agar to soak in the acidified water 15 min. (3) Remove the fibre agar and wash thoroughly with water until quite free from any trace of acid reaction to litmus paper. (4) Squeeze in a cloth to get rid of excess of water. (5) Use in the preparation of media, to give a 3 per cent sol. of agar, calculating from the weight of the agar in the original dry condition. Ml-12. (1) Prepare :— Fibre agar 10 ; bouilloni (M2*lll) 500. (2) Allow to soak 2 hr. (3) Bring into sol. with heat. (4) Convert into agar bouillon (M2*13). Note. — ^Instead of using bouillon the fibre agar may be allowed to soak overnight in water and the water removed in the morning. Ml*13.— (1) Prepare :— Fibre agar 10 ; water 500. (2) Dissolve with heat. (3) Filter. (4) Add the filtrate, made up to a volume of .500 c.c. to bouillon^ (M2*lll) of double strength. Note. — ^That is to say, bouillon made with 500 grm. meat to 500 c.c. water and containmg the same quantity of peptone and sod. chloride as is used for 1000 c.c. ordinaiy bouillon. Ml-2 POWDERED AGAR: Ml-21.— (1) Use in weighed quantities r5 to 2 per cent, by simple addition^ directly to the meat extract in the same way (M2"lll) as peptone and sod. chloride are added. Note. — The powdered agar should be made up into a paste or .suspension with a lit'U mMt exirx::?. b^fora aliitioa to ths remainder of the meat extract, ( 66 ) J