Test questions

What is the main stain for acid-fast staining?

Carbol fuchsin

What color indicates acid-fast positive bacteria?

Pink or red

What is the secondary stain for acid-fast staining?

Methylene blue

Why do we use acid alcohol in acid-fast staining?

It removes stains from all bacteria except mycobacterium due to its mucus.

Name the procedures that require fixing the smear.

Gram stain, Endospore stain, Acid-fast stain, Capsular stain

What are the differential staining procedures?

Gram stain, Endospore stain, Capsular stain, Acid-fast stain

What is the primary stain for Gram stain?

Crystal violet

What is the primary stain for Capsular stain?

Crystal violet

What is the primary stain for Acid-fast stain?

Carbol fuchsin

What is the primary stain for Negative stain?

Nigrosin

What is the primary stain for Simple stain?

Methylene blue

What is the primary stain for Endospore stain?

Malachite green

What is the counterstain for Gram stain?

Safranin

What is the counterstain for Endospore stain?

Safranin

Is the smear fixed for Simple stain?

Yes

Is the smear fixed for Negative stain?

No, to preserve the shape

What is the function of the Eyepiece (Ocular Lens) in a microscope?

It is the lens at the top that you look through.

What do the Objective lenses in a microscope do?

Magnify the image at 4x, 10x, 40x, and 100x.

What is the role of the Revolving nosepiece in a microscope?

Holds the objective lenses and allows switching between magnification powers.

What is the function of the Stage in a microscope?

It is the flat surface where you place the slide.

What are Stage clips/Mechanical stage used for?

Holds and moves the slide across the stage.

What does the Diaphragm do in a microscope?

Controls the amount of light passing through the specimen.

What is the function of the Illuminator (Light Source)?

Provides light to shine up through the specimen.

What is the purpose of the Condenser in a microscope?

Focusing and concentrating the light onto the specimen.

What is the function of the Coarse Adjustment Knob?

Brings the specimen into rough focus.

What is the function of the Fine Adjustment Knob?

Sharpen and fine-tune the focus of the image.

What do the Arm and Base do in a microscope?

Hold the microscope together.

What is the difference in smear preparation for broth and solid agar?

With broth, no water is added; with solid agar, one drop of D.I. water is used.

Why is iodine used in Gram stain?

To ensure that the crystal violet penetrates the bacteria.