MODIFIED OXIDASE TEST

 

 

Modified oxidase test which is also known as Microdase test is specifically used to identify Micrococcus and to differentiate Micrococcus from Staphylococcus species.

REAGENT:

          1% Tetramethyl p-phenylenediamine dihydrochloride in 6% Dimethyl sulfoxide (DMSO).

PROCEDURE:

1.    Take a commercially available Modified oxidase disk and place it on a slide.

2.    Pick the test inoculum using a tooth pick/wooden stick and smear it on the disk.

3.    Observe for colour change within 60 secs.

INTERPRETATION:

          Positive – Immediate formation of deep blue/violet colour at the site of inoculation.

          Negative – No colour change.

EXAMPLES:

 

POSITIVE ORGANISMS	NEGATIVE ORGANISMS
Micrococcus sp.	Staphylococcus sp. Except 3
Staphylococcus lentus
Staphylococcus sciuri
Staphylococcus vitulinus