Purpose and use:
The SODIUM DEOXYCHOLATE test is designed to quickly and easily differentiate Streptococcus pneumoniae from viridans streptococci.
Principle:
The test involves the solubility of S. pneumoniae colonies in sodium deoxycholate. In contrast, colonies of viridans streptococci are not altered by sodium deoxycholate.
Procedure:
There are two modifications of the test:
- Resuspend the tested strain in 0.5 ml of saline (turbidity value of 1–2 on McFarland scale) and add 3 drops of sodium deoxycholate. Incubate for 30 min. at 37 °C.
- Dispense 1 drop of sodium deoxycholate on the tested strain grown on blood agar and incubate for 30 min at laboratory temperature.
NOTE: Use a suspension of the tested strain in saline without sodium deoxycholate as a control.
Reading the results and evaluation:
After incubation:
- Modification 1: Clearing occurs with pneumococci. In case of viridans streptococci and controls, the suspension remains unchanged and turbid.
- Modification 2: Within 30 minutes after the tested strain is exposed to sodium deoxycholate, the colonies of pneumococci dissolve compared to those of viridans streptococci, which remain unchanged.
Notice:
- The SODIUM DEOXYCHOLATE test is supplied in doses of 3 ml (Cat. No. PT 102) and is for in vitro use only.
- Store sodium deoxycholate at laboratory temperature and use by the expiry date on the label.
- If the primary packaging of the IVD is damaged, do not use and contact the manufacturer.
- Dispose of unused IVDs and empty packaging in accordance with the Waste Act No. 185/2001 Coll.