Negative staining

Question 1

negative staining

Answer 1

does not stain the bacteria but stains the background

Question 2

why is heat fixing not used?

Answer 2

so that they can be viewed as unchanged as possible

Question 3

why is negative staining useful?

Answer 3

when other staining techniques fail in determining cell morphology or size. 
Ex coccobacilli (short oval bacilli) are difficult to stain

Question 4

steps to negative staining?

Answer 4

1. small drop of nigrosin near one end of the slide, then mix a loopful of culture from broth, for solid media mix a loopful of water in the niogrosin
2. gently take a second slide and slightly touch the nigrosin
3. push the slide along the entire surface of the slide
4. let the smear air dry

Question 5

to thick of a stain?

Answer 5

can cause cracks

Question 6

to thin

Answer 6

you can’t see anything