Microbiology: Chapter 3 True/ False Flashcards

1) The counterstain used in the Gram stain is a basic dye.

2) In a completed Gram stain, gram-negative bacteria are colorless.

3) In a completed Gram stain, gram-positive bacteria are purple.

4) If acid-fast bacteria are stained with the Gram stain, they will stain gram-negative.

5) The limit of resolution of the compound microscope illuminated with visible light is approximately 0.2 μm.

6) Both phase-contrast microscopy and differential interference contrast microscopy are used to

view the internal structures of cells without staining.

7) Cells viewed in darkfield microscopy appear similar to those stained with the negative stain.

8) The capsules and flagella of bacteria can be observed in gram-stained smears.

9) The greater resolution of the electron microscope compared to the compound microscope is due to the longer wavelengths of the electrons used to examine specimens.

10) Scanned probe microscopy is used to examine fine detail of molecular complexes, such as blood clots, or molecules, such as DNA.