Question

If you were working with an unlabeled simple stained smear, would you be able to identify the bacterial species by observing the slide under the microscope? Why or why not.

How would you differentiate between two species of bacteria that are present on the same slide and both of them are Gram-negative?

Answer 1

Generally the bacteria are stained with different type of stain like -Gram Stained which is very much helpful for visualization of the bacteria,the bacteria are so small in size that with out proper stain it is almost impossible to identify the bacteria is gram positive or gram negative.

• (A) Yes,With unlabeled simple stain bacterial species can be identified as the bacterial species are identified on the basis of the shape of the bacteria (For example-Cocci,Bacilli,Spiral etc.)
• (B) But the different type of species like the-Bacilli,Cocci can be identify if they are both gram negative as they are identified by the basis of body shape feature,which can be observe with out any stain.

Under proper magnification power we can identify different species of bacteria but the Gram positive and gram negative can not be differentiate with out staining.