Exploring Microscope Techniques in Food Science

The video tutorial covers the process of Gram staining to identify bacteria in yogurt samples. It explains the use of a light microscope, including safety procedures, focusing techniques, and the use of an oil immersion lens for better clarity. The tutorial also discusses the identification of Gram-positive and Gram-negative bacteria and the importance of cleaning and sterilizing lab equipment.

Who developed the Gram staining technique?

• Hans Christian Gram

• Robert Koch

• Louis Pasteur

• Alexander Fleming

Which of the following is NOT a basic lab safety procedure?

• Cleaning equipment after use

• Eating and drinking in the lab

• Wearing gloves and safety glasses

• Washing hands before and after handling materials

What is the purpose of the diaphragm on a microscope?

• To hold the slide in place

• To move the stage up and down

• To adjust the amount of light on the slide

• To magnify the image

What should you do first when preparing to use a microscope?

• Add immersion oil to the slide

• Turn on the light source

• Rotate the nose piece to the highest magnification

• Make sure the microscope is plugged in

What is the total magnification when using a 10x objective lens with a 10x eyepiece lens?

• 100 times

• 400 times

• 10 times

• 40 times

Which knob should you use first to focus the image?

• Diaphragm adjustment knob

• Fine adjustment knob

• Light source adjustment knob

• Coarse adjustment knob

What is the total magnification when using a 40x objective lens with a 10x eyepiece lens?

• 10 times

• 100 times

• 40 times

• 400 times

What is the purpose of using immersion oil with the 100x objective lens?

• To prevent light distortion and improve image clarity

• To protect the slide

• To magnify the image further

• To clean the lens

What color do Gram-positive bacteria appear after Gram staining?

• Pink

• Blue

• Green

• Purple

What should you do with the slide after finishing the experiment?

• Throw it away

• Leave it on the microscope

• Clean it and sterilize it in the autoclave

• Store it in a drawer