Microbiology help PLEASE!!! My major unknown may be contaminated?

Nursing Students Pre-Nursing

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So I am in microbiology class, a prerequisite for the Registered Nurse (RN) Program at my local college.

A gram stain under the microscope shows a lot of gram negative (pink) cells, but a few gram positive (purple) cells as well. Mostly the pink cells. The purple ones are smaller cells, and there appears to be less of those.

Any tips on isolating the cells? I only want the gram negative, pink cells. Asking for a whole new specimen would cost 40 out of the 100 points. Ouchhhh :/!!!

Which objective lens did you view your bacteria under? There are plenty of bacteria on your smear. You need to use 40x-100x objective lens to see morphology and arrangement.

Specializes in ICU.

Yes, you need to hone in on that a lot more to even begin to tell what they are.

Specializes in Hospitalist Medicine.

First of all, we can't give you a direct answer of "what is it?" This is your project and you need to come up with the answer on your own.

There are several tests you can do to determine if the sample is gram positive or negative. You need to follow a logical process of elimination.

Second, the pics you posted are using the wrong magnification. You need to be on 100x so we can see the actual shape. Again, even if we look at it, we can't give you the answer. We can prompt you in the right direction, but you need to come up with the answer.

Good luck! :)

This actually happened to me and the problem was I decolorized for a second too long. So I had a few purple but everything else looked more pink. You may just want to do the gram stain again and see if you get a different result.

Yeah, that needs 100x and oil

Mostly asking for tips not direct answers on what it is.

I think i'll try gram staining with staphylococuss (+) and e coli (-) on the same slide. That way I can tell if i'm doing it wrong.

Cause the little purple dots are making me think that it's contaminated with another bacteria, when it probably isn't!

Also the pic is on 100x magnification, its just a cellphone photo so its not super greatly detailed, but the purple dots can be seen! Hopefuly that streak plate method of isolation works :) Thanks everyone

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