DNA – November 19, 2010 Describe the proper way to carry a microscope. What is the function of the diaphragm on a microscope? Describe the proper way to store a microscope.

Identify the Parts

Introduction to Microscopes Day 2 Ms. Klinkhachorn November 19, 2010 Biology

Calculating Magnification To calculate the total magnification using a compound light microscope, you must always multiply the power of the ocular lens by the power of the objective lens. Total Magnification = Ocular Lens Power x Objective Lens Power

Sample Problem #1 Jared’s microscope has an ocular lens power of 20. He sets his objective lens power to 10. What will be the total magnification of the object he is observing? Ocular lens = 20 Objective lens = 10 Total Magnification = 20 x 10 = 200

Sample Problem #2 Shelley’s ocular lens has a power of 50. She is looking at a cell under an objective lens of 20. What will be the total magnification of the object she is looking at?

Sample Problem #2 Shelley’s ocular lens has a power of 50. She is looking at a cell under an objective lens of 20. What will be the total magnification of the object she is looking at? Ocular = 50, Objective = 20 Total Magnification = 50 x 20 = 1000

Wet Mounts Use wet mounts to hold objects/specimens in place Can use this to view live organisms Often make the object easier to see under the microscope

Creating a Wet Mount Obtain glass microscope slide and cover slip. Clean with tissues and water if dirty. CAREFULLY place the specimen/object to be observed in the middle of the slide.

Creating a Wet Mount Add ONE (1) drop of water/liquid to the specimen/object. At a 45 degree angle, SLOWLY and GENTLY lower the clean cover slip on top of the drop and the specimen/object. Wipe any excess water off the slide before viewing with a tissue.

How to Focus Images Using a Microscope Place slide on stage. Use clips to hold slide down. Start with the LOWEST POWER objective. Use the coarse adjustment knob to focus the image. It should be CLEAR and SHARP.

How to Focus Images Using a Microscope Rotate the objective lens to the next highest power. Do NOT touch the coarse adjustment knob any more. This will only make the image worse. Use the fine adjustment know to make the image sharper. Repeat steps 3 through 5 with the higher power.

The Letter “e” – 100x

The Letter “e” – 250x

The Letter “e” – 400x