Lab 2 & 3 Review: Microscopy, Culture Morphology, and Staining

Flashcards covering microscopy, bacterial culture morphology (broth, agar plates, slants, stabs), and staining techniques (smears, simple stains, differential stains) based on the lecture notes.

What are some common culturing methods for bacteria?

Broth, Agar Slant, Agar Plate, Agar Stab, and Gelatin Stab.

How is colony size categorized on agar plates?

Punctiform (

Name some types of colony forms found on agar plates.

Circular, Irregular, Rhizoid, Filamentous.

What are common colony margins observed on agar plates?

Entire, Undulate, Lobate, Curled, Filamentous.

Describe various colony elevations on agar plates.

Flat, Raised, Convex, Pulvinate, Umbonate.

What are some characteristic morphologies of slant cultures?

Filiform (thread-like), Arborescent (tree-like), Beaded, Effuse (spreading), Rhizoid, Echinulate (spiny).

What types of growth patterns can be observed in broth cultures?

Pellicle (surface film), Ring (growth at surface), Sediment (growth at bottom), Flocculent growth (clumps), and Turbid growth (cloudy).

Identify characteristic morphologies of stab cultures.

Filiform, Beaded, Villous.

What are the key learning objectives for the microscopy lab?

Review how to use a compound microscope, learn how to make specimen slides, and learn how to measure microscopic objects.

What is a crucial rule for cleaning microscope lenses?

Use only lens paper to clean lenses.

Name the four objective lenses commonly found on a compound microscope.

4x, 10x, 40x, and 100x.

Which controls on the mechanical stage allow for moving the slide?

Side-to-side and front-to-back controls.

What is the correct procedure for changing objective lenses?

Turn the objective by the revolving nosepiece, never by the objective lens itself, and ensure enough space between the objective and the slide.

Which objective lens should you always start with to find a specimen?

The 4x objective lens.

Which objective lens requires immersion oil?

The 100x objective lens.

How should you clean the 100x objective after using immersion oil?

Rotate away from the 100x objective, remove the slide, and use lens paper to blot the oil off the 100x objective.

What are the three basic shapes of bacteria?

Cocci (spheres), Bacilli (rods), and Spiral.

What is a bacterial smear?

Thinly spreading bacteria on a slide.

What is the purpose of staining bacteria?

To dye the bacteria so they can be seen against a background, as stains are usually positively charged dyes attracted to negatively charged nucleic acid and cell walls.

What is the difference between simple staining and differential staining?

Simple staining uses one color to help see bacteria against the background, while differential stains help identify and differentiate different types of bacteria.

Give examples of differential stains.

Gram stains, Negative Staining, Acid-Fast Staining, and Endospore Staining.

How do you prepare a bacterial smear from a solid medium?

Place one to two loopfuls of water on the center of the slide, then transfer a small amount of bacterial inoculum into the water, spreading both into a thin area.

What is the first step in a simple staining procedure using methylene blue?

Place the slide on the staining tray and flood the smear with methylene blue, allowing 1 to 2 minutes of exposure.