Tuesday, May 17, 2016

Protocol for catalase and Oxidase test for bacterial cells


Protocol for catalase and Oxidase test for bacterial cells

1.     Catalase Test:

Procedure:
1.      Transfer a small amount of bacterial colony to a surface of clean, dry glass slide using a loop or sterile wooden stick
2.      Place a drop of 3% H2O2 on to the slide and mix.
3.      A positive result is the rapid evolution of oxygen (within 5-10 sec.) as evidenced by bubbling.
4.      A negative result is no bubbles or only a few scattered bubbles.
5.      Dispose of your slide in the biohazard glass disposal container.


Reagent:
1.      3% H2O2
-Take 1 ml 30-35% H2O2 and add 9 ml D/w.
Catalse test


2.     Oxidase Test:

Procedure: (Wet Filter Method)
1.    A strip of filter paper is soaked with a little freshly made 1% solution of tertramethyl-p-phenylene-diamine dihydrochloride reagent.
2.    A speck of culture is rubbed on it with a platinum loop.
3.    A positive reaction is indicated by an intense deep-purple hue, appearing within 5-10 seconds, a “delayed positive” reaction by colouration in 10-60 seconds, and a negative reaction by absence of colouration or by colouration later than 60 seconds.
 
Oxidase test

Procedure: (Dry Filter Method)
1.    Strip of Whatman’s No. 1 filter paper are soaked in a freshly prepared 1% solution of tertramethyl-p-phenylene-diamine dihydrochloride.
2.    After draining for about 30 seconds, the strips are freeze dried and stored in a dark bottle tightly sealed with a screw cap.
3.    For use, a strip is removed, laid in a petri dish and moistened with distilled water.
4.    The colony to be tested is picked up with a platinum loop and smeared over the moist area.
5.    A positive reaction is indicated by an intense deep-purple hue, appearing within 5-10 seconds, a “delayed positive” reaction by colouration in 10-60 seconds, and a negative reaction by absence of colouration or by colouration later than 60 seconds.

Reagents: 1% tetramethyl-p-phenylene-diamine dihydrochloride
-1 g tetramethyl-p-phenylene-diamine dihydrochloride and add 100 ml d/w



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