A. Test tube Method
1.Prepare a suspension of the organism by adding few colonies from freshly isolated bacterial growth (18-24 hour) in a test tube containing 1-2 ml of sterile saline.
2.Shake or vortex to form a uniform suspension. Adjust the suspension to that of 0.5-1 McFarland standard.
3.Divide the organism suspension equally into two tubes, one labeled TEST and other labeled CONTROL.
4.Dispense 2 drops of 2% sodium desoxycholate into the tube labelled TEST. Add 2 drops of saline to the labelled CONTROL.
5.Gently mix each tube.
6. Incubate the tubes at 35-37°C.
7.Observe the tubes for clearing of turbidity after 10-15 minutes. Examine each tube by Gram-staining or Methylene blue wet mount for lysis of the cell. If negative, continue to incubate up to 3 hours. Observe again for clearing.