Question

What is meant by Gram positive and Gram negative bacteria?

Answer 1

Gram positive bacteria are those bacteria which can retain the crystal violet dye because of the thick layer of peptidoglycan and are stained purple with low resistance against antibodies and more resistance to drying and physical disruption and they can produce primary exotoxins.

Gram negative bacteria on the other hand are stained red or pink as they do not retain the crystal violet dye because of thin layer peptidoglycan with more resistance against antibodies because of impenetrable membrane but they have low resistance to drying and physical disruption and they can produce primary endotoxins

Answer 2

Gram staining

Step by step explanation:

• Gram staining is a differential staining technique used to stain bacteria.
• Gram stain differentiate bacteria in two groups: a) Gram positive bacteria. b) Gram negative bacteria.
• Gram positive bacteria: These bacteria during staining resist decolourisation and the primary stains remain, giving them violet color. The peptidoglycan layer of gram positive bacteria is thick and contains great amount of teichoic acid.
• Gram negative bacteria: During staining, these bacterias easily get decolourised by organic solvent and when counter stained  they appear red. Peptidoglycan is thin in gram negative bacteria.