Gram Stain?

About microscopic forms of life, including Bacteria, Archea, protozoans, algae and fungi. Topics relating to viruses, viroids and prions also belong here.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
Bioslave
Garter
Garter
Posts: 20
Joined: Mon Jan 28, 2008 5:51 am

Gram Stain?

Post by Bioslave » Wed Feb 27, 2008 2:19 am

What is the purpose of using iodine for the gram stain? thanks.

blcr11
Viper
Viper
Posts: 672
Joined: Fri Mar 30, 2007 4:23 am

Re: Gram Stain?

Post by blcr11 » Wed Feb 27, 2008 4:55 pm

It's a mordant. It forms an insoluble complex with the primary Gram stain, crystal violet or methylene blue, and helps keep the dye stay put once it has bound to wherever it binds. It probably also adds something to the color, but its main function is to keep the dye fixed to the sample.

Cat
King Cobra
King Cobra
Posts: 635
Joined: Thu Feb 14, 2008 7:40 pm

Post by Cat » Wed Feb 27, 2008 4:59 pm

Iodine (mordant) forms complex with crystal violet that cannot be washed out from gram +ve cells because of thick layer of peptidoglycan.

Bioslave
Garter
Garter
Posts: 20
Joined: Mon Jan 28, 2008 5:51 am

Re: Gram Stain?

Post by Bioslave » Wed Feb 27, 2008 7:31 pm

thanks to both of you..

Bioslave

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests