abacus49

I'm not sure if you are looking for a more detailed explanation or not but a gram positive bacteria will absorb india ink into it's cell wall whereas a gram negative will not. When one is trying to identify a bacteria culture on a slide the process is to dip the slide into the ink and then rinse it off. The bacteria will retain the dye or it wont and that is why they are referred to as positive or negative. Hope this helps and isn't too simplistic.

My son has a question for his science class and I am not knowledgable about the subject so I am looking for some help. Can a microscope make the beam from a laser more powerful?