Final answer:
Heat fix a urine sample before Gram staining to observe the shape and Gram reaction of bacteria, which can be purple (Gram-positive) or pink/red (Gram-negative). Endospores may be seen as clear areas in Gram stain, but would appear as distinct green structures in an endospore-specific stain.
Step-by-step explanation:
In biological specimen preparation for microscopy, certain types of samples may require gentle treatment with heat prior to staining to help fix the microorganisms to the slide. This process, commonly referred to as heat fixing, typically involves passing the slide through a flame. However, for samples such as urine, gentle heat without flaming is sufficient to prevent the distortion of cells.
Gram Stain of Urine Sample
Name of Gram stained culture: Urine
Gram stain reaction and cellular morphology: The urine culture Gram stain would reveal the primary shapes of bacteria, which could be rod-shaped (bacilli) or spherical (cocci), and their Gram reaction would be either positive (purple) or negative (pink/red).
Are endospores visible in the Gram stained smear? Endospores may or may not be visible in a Gram stained smear of a urine culture; it depends on whether the bacteria present are capable of forming endospores.
If you see endospores, describe how they appear in the Gram-stained preparation, and how this is similar to and different from what you see in the endospore-stained preparation: In a Gram stained smear, endospores typically appear as clear areas within the bacteria because they are resistant to staining. In contrast, in an endospore stained preparation, they would be stained with Malachite Green and stand out as green structures within or next to the red/pink cells.