MOTILE BACTERIA

Sample for examination of microorganism is suspended in a fluid and examine microscopically for identification of motile bacteria. On this occasion, it could be examine that many bacteria are seen moving. They move from one position to another. A motile organism is the organism that change it position do to the present of other organisms. Below are the step taken for the preparation of film for examination of motility of bacteria.

• On a clean glass slide with a 22mm squire cover slip.
• Make plastacine ring about 2cm long 1.2cm breath diameter at the center of the slide, but for alternative well slides. With depression in the center can be used.
• Transfer a loopful of the culture colony to the center of the cover slips.
• Carefully press the ring of the plastticine onto the coverslip makes sure the colony in the center of the pasticine so that it does not come in contact with the plasticine. It very necessary for the cover slip to seal with the slide, otherwise false motility is bound to take place.
• For quick movement of bacteria, invert the slide so that the cover slip is upper most.
• Examine by microscopy focusing first onto the edge of the drop with X40 objective and if focus swinging around use X10 objective to investigate motility.
• Discard all the preparation into a jar containing a disinfectant, care should be taken so that the disinfectant should not penetrate into the ring and kill the colony.

WET PREPARATION

• Mix the specimen in a small drop of saline, iodine or stain on a glass microscopic slide.
• Place cover slip onto the suspension and care should be taken so that the specimen should not escape through the edge of the cover slip.
• Paint the cover slip edge with paraffin wax or Vaseline so that it prevents overflow or evaporation of the sample and examine microscopically.