Suppose you perform a gram stain on a sample from a pure culture of bacteria and observe a field of red. What does it mean?

Answer by  HH (404)

It depends, if the red is associated with bacterial cells. If that is the case, your bacterial culture is composed of Gram-negative cells. If the red is not associated with cells and spread over the microscope slide, then the washing off of the stain was not sufficient enough, resulting in the red background.

Answer by  kw35 (54)

A red gram stain indicates the bacteria are gram-negative. These bacteria have thinner cell walls than gram-positive bacteria. Gram-positive bacteria appear purple, gram-negative appear red or pink.

Answer by  worker5534 (518)

Two types of bacteris are there on the basis of the gram stain. There are gram negative bacteria and gram positive bacteria. Suppose you perform a gram stain on a sample from a pure culture of bacteria you may observe a field of red.