Question

Exercise 8 - Gram Staining Procedure for gram staining. Know all chemicals/reagents used in correct order, function of each chemical, the effect of cach chemical and how gram + and gram - bacteria would appear at each step Color reactions at each step of procedure. Know why, based on the differences in cell wall structure, that the gram + vs gram - bacteria stain either purple or pink. What washes off in the decolorizing step of a gram - bacteria? Know reactions +/-, shapes and arrangements for organisms (Genus and species) we used. Be able to recognize the appearance of a gram + vs. gram - bacteria from a stained slide and identification of bacteria on it. Fill in the following Table: Gram Stain Name of Function Chemical/Reagent crystal Violet Primakstail Gram's rodone Mordant 1 secolova Sazranan Countersto Exercise 9 - Spore Staining Appearance of Gram + cells - Purple Purple Purple Appearance of Gram - cells Purple Purple Color Less Pink Structural basis for staining result: spores are multilayered, heat resistance structures Difference in Schaeffer-Fulton and Dorner Spore Staining Methods. The names of all the chemicals/reagents used and functions. What would spore and sporangium look like for each method? Names three spore forming genera. Know the name of any 5 diseases of spore forming bacteria we discussed. Know name (Genus and species) of the spore forming organism we used in lab. Be able to recognize the appearance of a either spore stain method from a stained slide and identification of the bacteria on it. Fill in the Following Table: Schaeffer-Fulton Spore Stain Method Function Outcome Name of Chemical or Step Malachite Green Heat I Saxranen Primary stain Greenspore mordant counterstad Green spore

Answer 1

Exercise 8 :-

Chemical agent :-

1. Crystal violet . It's function is primary stain . Appearance of gram +cells is purple and appearance of gram - cells is purple.

2. Grams stain -it functions as mordant. Appearance of gram +cells is purple and appearance of gram - cells is purple.

3. Ethyl alcohol . It's function is decolouriser. Appearance of gram +cells is purple and appearance of gram - cells is colourless.

4. Safranin. It's function is to counter stain. Appearance of gram +cells is purple and appearance of gram - cells is pink