Staining

Question 1

Acid-Fast stain

Answer 1

• -good for staining microorganisms with waxy outer walls
• -first stain with carbol-fuschin
• -then rinse with an acid alcohol
• -then counterstain with methylene blue

Question 2

Negative Stain

Answer 2

• -stain for glycocalyx
• -first stain with nigrosine (or any bulky, negatively-charged molecule that cannot penetrate the glycocalyx) by mixing sample then spreading over the slide
• -counterstain with crystal violet

Question 3

Endospore stain

Answer 3

–stain with malachite green using moist heat

counterstain with safranin

Question 4

Flagella stain

Answer 4

Stain with leifson stain which is CV and a mordant (phenol, tannic acid, potassium aluminum sulfate)