Question..........................3 - psychmledr

[ArchivalUser]

The purpose of using 95% alcohol or alcohol-acetone during the Gram stain procedure is:

A. To facilitate the entry of the purple dye into Gram negative cells
B. To form a complex with the iodine solution
C. To adhere the cells to the slide
D. To disrupt the outer cell membrane so the purple dye can leave the bacteria
E. To retain the purple dye within all the bacteria

[ArchivalUser]

dd

[ArchivalUser]

D.. iodine gives color and ethanol removes it

[ArchivalUser]

If grams iodine gives the colour then what is the role of crystal violet dye ?

[ArchivalUser]

first crystal violet gives color,but iodine will keep it like that. like retain the color.
n then u have 2 treat it wid alc .

[ArchivalUser]

"D" is correct.

As Sarah explained, Crystal-violet stains all cells blue/purple.
Iodine will fthen orm a complex with crystal violet which still maintains the blue color of cells

Ethanol or acetone will remove the crystal violet-iodine complex from the Gram negative bacterial cells more than the Gram pos because Gram negative have more lipids and a thinner peptidoglycan layer in their cell wall.

Thank you.

[ArchivalUser]

D