NEGATIVE STAIN Flashcards

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1
Q

What dye is used for negative stains?

A

Acid dye nigrosin, it has negative charge chromophores

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2
Q

Will the cells remain unstained and have a dark coloured background in the negative stain experiment?

A

Yes

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3
Q

Why can’t methylene blue be used in place of nigrosin for negative stain?

A

methylene blue is a basic stain and it will adhere to the slightly negative bacteria
-> Nigrosin is an acidic stain

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4
Q

What are the practical advantages of negative staining?

A

cells will retain their natural sizes and shape, therefore, not distorted by heat

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5
Q

Why doesn’t nigrosin penetrate bacterial cells?

A

because it is negatively charged

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