Optochin Discs are used for identification and differentiation of Streptococcus pneumoniae and Viridans Streptococci.
Directions :
1. Prepare Mueller Hinton Agar Plates with addition of sterile defibrinated blood.
2. Inoculate the entire agar surface of the plate three times, rotating the plate 60° between streaking to obtain even inoculation.
3. Swab the rim of the agar bed too.
4. Immediately place Optochin disc in the centre of the plate.
5. Tap the discs with some sterile needle or forceps after placing them on the agar for complete contact with the medium surface.
6. Invert the plates and incubate at 35°C-37°C for 18-24 hours.
Appearance: Filter paper discs of 6 mm diameter with printed “OP 5” on each side of the disc.
