Adding distilled water to the slide before staining serves to:

Adding distilled water to the slide before staining serves to:

• A. Hydrate bacteria during staining
• B. Allow bacteria to dry onto the slide and then fix with heat
• C. Dilute stains for even application
• D. Sterilize the slide before examination

Answer: (B)

Making a proper bacterial smear starts with creating a thin, evenly distributed layer of cells on the slide. Distilled water is added to suspend the cells so they spread into a uniform film as the drop is spread and allowed to air-dry. Once dry, heat-fixation immobilizes and kills the cells by denaturing proteins, so they stay attached during staining and won’t wash off. This step ensures more consistent staining and preserves cell morphology. It isn’t about hydrating during staining, diluting stains, or sterilizing the slide.

Making a proper bacterial smear starts with creating a thin, evenly distributed layer of cells on the slide. Distilled water is added to suspend the cells so they spread into a uniform film as the drop is spread and allowed to air-dry. Once dry, heat-fixation immobilizes and kills the cells by denaturing proteins, so they stay attached during staining and won’t wash off. This step ensures more consistent staining and preserves cell morphology. It isn’t about hydrating during staining, diluting stains, or sterilizing the slide.