-ve staining of bacteria:

[sinjanj]

I was giong through "BIOLOGICAL SCIENCES by NPO GREEN...

I came across a section called Capsules of Bacteria...

It says ... "Capsules are slimy or gummy secretions of certain bacteria which show up clearly after negative staining(when background , rather than the specimen, is stained)

With regard to this I wanted to ask the following questions..

a> Does this negative staining refer to gram staining?? But something will show up only if its a gram positive bacteria.... Plz help me to understand this..

b>What do you actually mean by staining the background??

Friends.. Plz answer in simple language... I just need to understand.. I am not pro..plz..simple language

Dear friends.. I am waiting for your answers... Plz help me asap

[MrMistery]

No, it does not refer to Gram staining. There are many stains used in microbiology. Heck, i myself did 3 or 4 of them in a lab a few years back. However, I never heard of this background staining. What is probably done is to add a stain that selectively binds the growth medium(which is not hard, just make sure your medium contains something that the bacteria can't possibly contain and stain that). Your bacteria will show up white on whatever color the stain is. This is probably done because stains interact with the cell wall of the bacteria, which can take up dyes like a sponge, and the capsule prevents this interaction.
Cheers

[sinjanj]

Thanks bro...!!!

[canalon]

Negative staining can simply be adding a drop of ink to the solution where the bacteria are suspended under your microscope. The field will turn black, but the bacteria with capsule will not take up the ink and will appear as light dots on the dark background.

[MrMistery]

So i was almost right.
Thanks Patrick