Why determine motility and h2s before adding kovac's reagent?

Answer 1

You will do this regardless since Indole is part of the SIM media....this media will turn black if H2S is present and you read it for motility just like standard motility media. It must incubate for 24-28 hrs before doing the indole portion. Hope this helps.

Answer 2

Determining motility involves observing the movement of bacteria, which can be hindered by adding Kovac's reagent as this reagent can affect bacterial motility. Also, hydrogen sulfide production (H2S) is an important characteristic that can help differentiate bacterial species before adding Kovac's reagent, which is used to detect indole production. Waiting to add Kovac's reagent until after these tests ensures more accurate results.

Answer 3

because kovac's reagent is used for indole production test and for both mean indole and H2S test SIM Medium is used and it is possible to do both test together for one particular organism.

it is also possible that org. show both positive or both negetive.

if SIM Medium converk black mean H2S production and after kovac reagent addition if a red ring is formed mean indole production.

there is no requirement of any reagent addition for H2S TEST.