Micro students may find this presentation on culture methods useful..

1. CULTURE METHODS G.HARIPRASAD M.Sc.Med Micro M.Phil LECTURER THOOTHUKUDI GOVT. MEDICAL COLLEGE THOOTHUKUDI

4. STREAK CULTURE Routinely used method to isolate bacteria. One loopful of culture is made as a primary inoculum and is then distributed thinly over the plate by streaking it with the loop in a series of parallel lines in different segments of the plate. Loop flamed and cooled between the different sets of streaks. On incubation growth may be confluent at the site of the original inoculation but becomes progressively thinner and well separated colonies are obtained over the final series of streaks

5. LAWN CULTURE Also called as carpet culture. Provides a uniform, growth of the bacterium. Useful for bacteriophage typing and antibiotic sensitivity testing. Also used in the preparation of bacterial antigens and vaccines. Prepared by flooding the surface of the plate with a liquid culture or suspension of the bacterium, pipetting off the excess inoculum and incubating the plate. Alternatively the surface of the plate may be inoculated by applying a swab soaked in the bacterial culture or suspension.

6. COTTON SWAB IS DIPPED IN CULTURE NEAR FLAME SWAB CHARGED WITH CULTURE IS SWABBED ON PLATE

7. ANTIBIOTIC SENSITIVITY TESTING

9. STAB CULTURE Prepared by puncturing with a long straight, charged wire in a suitable medium such as nutrient gelatin or glucose agar. Medium is allowed to set with the tube in the upright position, providing a flat surface at the top of the medium. Employed mainly for demonstration of gelatin liquefaction and oxygen requirement of the bacterium under study. Also used in the maintenance of stock culture.

10. POUR PLATE CULTURE Tubes containing 15 ml of the agar medium are melted and left to cool in a water bath at 45 ºC-50 ºC. Dilutions of the inoculum are added in 1 ml volume to the molten agar, mixed well. Contents poured in sterile petri dishes and allowed to set. After incubation colonies will be seen well distributed throughout the depth of the medium. Enumerated using colony counters. Gives an estimate of the viable bacterial count in a suspension and is the recommended method for quantitative urine cultures.

11. COLONY NUMBERS DECREASES WITH SERIAL DILUTION

12. COLONY COUNTER

17. METAL JAR PLASTIC JAR

18. GAS PAK CATALYST

20. ANAEROBIC SETUP