Lab #2 Foldscope

.docx

School

Normandale Community College *

*We aren’t endorsed by this school

Course

1100

Subject

Biology

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by BarristerDiscoveryHorse21

Lab #2: Foldscope Learning Outcomes Learn how to construct and use a Foldscope Observe different cells using the Foldscope Dr. Gonsar’s thoughts on using the Foldscope It takes a lot of time and patience. It can be frustrating trying to figure this out, so I say start now!!! Have a good lamp handy so that you can look through the Foldscope into the lamp. I found that the best. Using a cell phone can be frustrating so I went back and forth. With the cell phone you can increase your magnification and I really like that, but it took time to get it set up and finding the focus could be difficult depending on the slide. Introduction to Microscopy In this lab you will put together your Foldscope and practice using it with the slides in the slide box that came with your Foldscope Deluxe tin kit. M ICROSCOPY TAKES TIME AND PATIENCE . Even if you have prior experience, you will need to spend time learning how to use the Foldscope. From the Foldscope User Guide Website https://www.foldscope.com/user-guide MICROSCOPY 101 A microscope consists of three essential components: a sample , a lens , and a light source . The sample, or specimen, is what you're looking at in your microscope. The lens is what magnifies the sample-- it makes it look larger by bending the light you see. Resolution is a measure of how clearly you can see things in a microscope. The resolution of a lens is the size of the smallest feature you can distinguish when looking through it. Foldscope’s resolution is 2 microns, which is about the length of an E. coli bacterium. One micron is 0.0001 cm. Most microscopes you might use in a classroom or laboratory are compound light microscopes . This means that their lenses are made of multiple pieces of curved glass, each piece similar to an eyeglass lens. In Foldscopes, our lens is a single glass ball. This is the same type of lens used in the very first microscope made by Antony van Leeuwenhoek in the 1600s! In Foldscope, as in most microscopes, it’s easiest to view a sample when it’s mounted on a slide , a flat rectangle that holds your specimen. Slides provide a stiff base for the sample and keep it secure for viewing. Slides are traditionally made of glass, but Foldscope can also be used with slides made of paper. A light source is important for illuminating the sample. In transmissive light microscopy , the light shines through the sample. This is the type of microscopy that Foldscope uses: the sample is in between the light source and the lens. Transmissive light microscopy is very effective for viewing samples that are thin and translucent, as the sample is only visible if it allows light through to the lens. Every microscope has a set focal length : the distance at which something viewed through the lens looks clear and crisp, not blurry. In a standard 140x Foldscope lens, the back focal length is 0.56 millimeters, about the thickness of 5 sheets of paper. This means that a Foldscope sample must be only 0.56 millimeters away from the lens to be viewed clearly-- so close it’s almost touching! This flatness is one reason Jim and Manu thought that paper would be a good material for building a microscope with this lens. When you focus a microscope, you move the sample farther or nearer to the lens until it is the right distance away. A sample that is out of focus will appear blurry. Depth of field is the thickness of your sample that appears in focus at the focal length. When you adjust the focus, the depth of field is like a three-dimensional window that moves forward and

backward through the sample, and everything within the window’s thickness appears clear. Foldscope’s depth of field is 13.6 microns, which is 0.0136 millimeters. Think about making a circle with your hand and looking through it with one eye-- you will only be able to see a small circle, but moving your head will let you see different things in that circle! This circle is called your field of view . Just like looking through your curled hand, all microscopes have a limited field of view: the lens allows you to see only a small area of any sample at one time. Moving your field of view is called panning . For a microscope, that means moving the sample relative to the lens, placing different areas of the sample beneath the lens. Materials You May Need to Provide: Light Patience Materials In Lab Kit: 1 Foldscope Single Pouch 1 Foldscope Premium Accessory Pack Lens paper Procedure If you haven’t already, open your Foldscope. Read the paper marked READ THIS FIRST! Read the safety warnings, disclaimers, and warranty on the reverse side. All the videos mentioned below can be found in D2L under Content è Week 2 è Lab #2 Foldscope Assemble your Foldscope 1. Watch the tutorial “How to assemble your Foldscope” without doing anything – just watch. 2. Watch the tutorial again and put your Foldscope together with the video. See Figure 1 for the correct pouch. ***The color of your pouch may be different than the one shown in Figure 1.*** Hint: Make sure you separate the round lens from the square coupler. They get stuck and can affect how the Foldscope works if they are not separated. Figure 1. Materials in the Foldscope Single Pouch. 3. At the end of the tutorial it asks you to make a slide. Do that and comment on it in Question 3 in the Lab Report at the end of this procedure.

4. Watch “How to Insert a Glass Microscope slide into Foldscope.” 5. Open your Foldscope Premium Accessory Pack (Black Pouch) and find the clear, plastic slide holder (see the arrow marked A in Figure 2 below). This slide holder contains five slides, three are blank and two are prepared slides. Take out the two prepared slides. Figure 2. Foldscope Premium Accessory Pack – Black Pouch 6. Watch “How to Insert a Glass Microscope slide into Foldscope” again and use one of the slides from the kit that came with your Foldscope to learn and practice how to use your Foldscope. You may want to watch the videos on D2L before you answer Questions 4-6 in the Lab Report. 7. If you have a cell phone and you are interested in using it watch “Foldscope viewing with your camera phone.” If you do not have a cell phone, proceed to #8. 8. Learning how to use the LED Magnifier will help with making sure you have enough light to see your specimens. Watch “How to use the LED Magnifier with Foldscope” to learn how to attach this light. See the arrow marked B in Figure 2. 9. Continue to practice with your Foldscope and these slides until you are comfortable using the Foldscope. 10. Complete the Lab Report. Lab #2: Foldscope Lab Report 10 points Answer the following questions. ( Hint – Read the introduction .) There may be multiple questions at each number. Answers should be written in complete sentences. 1. Why do microscopes have a limited field of view? 1pt. Every microscope has a constrained field of view, allowing you to observe just a portion of each sample at once. Panning is the movement of your field of view. Moving the sample in relation to the lens and positioning several sample regions under the lens are necessary for a microscope. 2. What is the total magnification of the Foldscope? How could you increase that magnification? 1pt.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version