Microbiology Lab 2

Question 0

What does heat fixing do?

Answer 0

Heat fixing kills the bacteria, and makes them adhere to the slide and coagulates the protiens for extra visibility through microscope. They distort the cells as well.

Question 1

What is simple staining. What kind of reagents do we use ? Can you describe the steps for simple staining?

Answer 1

Simple staining is the process of looking at cells with better observe meant of size and to see bacterial arrangement and morphology. The types of stains we use for simple staining is metheyne blue, safranin and crystal violet. Step one clean slides and add DI water to the slide, step 2 inoculate bacteria on to slide by using aseptic techniques, step 3 smear and mix should have cloudy appearance. Step 4 let it air dry. When air dried, time to heat fix. After heat fix let it cool and apply simple staining. Cover the smear with crystal violet, safranin or metheyne blue for one minute and rinse with DI water. After that gently dry with bibulous paper.

Question 2

Chemistry of basic stains

Answer 2

Basic stains have a positively charged chromogen while the negatively charged bacterial cell forms with it via a ionic bond.

Question 3

What is a gram stain?

Answer 3

This is a differential stain where a decolorizer ion step occurs between the application of two basic stains.