Lab Assignment free essay sample

Bacteria and Blood Abstract The purpose of this exercise is to gain knowledge on basic skills to correctly operate a microscope by viewing blood and bacteria through different magnifications Hypothesis This exercise will help me gain knowledge and the correct way to use a microscope. This will also help me for future observations of microbes. Methodology Properly set up microscope and made sure it was functioning properly. All lenses were wipe with lens paper and nine different slides were chosen upon inspection, two of which were fresh. Each slide was carefully observed at each magnification (4x, 10x, 40x). Â  | Clusters of erythrocytes| | 1500Xoil immersion| Lifesavor like shape| | | No nucleus seems to be formed| | | Erythrocytes stacked | Analysis It took some time getting used to the microscope because I haven’t had practice in a couple years. Once I stared getting my feet wet, it all seemed natural to me. Most of these slides were provided through the V scope, but the fresh yogurt slide and fresh blood smear were great practice techniques to use the microscope correctly. Conclusion All observations and drawings were noted as they appeared on the slides. This exercise was performed in the correct technique that was provided. A. List the following parts of the microscope and describe the function of each The following parts of the microscope: a. Eyepiece – transmits and magnifies the image from the objective lens to the eye. b. Tube – Connected to the arm of the microscope and can be adjusted up or down to bring the image into focus and also to change slides. c. Nosepiece – rotating mount that holds many objective lens d. Objective Lens – gathers lights from specimen e. Stage – where the specimen rests f. Condensor – a lens system that aligns and focuses the light from the lamp onto the specimen. g. Illumination Mirror – used to shed light on the specimen. The simplest illumination system is a mirror that reflects room light up to the specimen. . Coarse-focus Knob – brings the object into the focal plane of the objective lens i. Fine-focus knob – makes fine adjustments to focus the image. j. Arm – a curved portion that holds all of the optical parts at a fixed distance and aligns them. k. Clips – holds the specimen on the stage. When looking at a ma gnified image, even moving the specimen slightly can move parts of the image out of view. l. Base – supports the weight of all the microscope parts B. Define the following microscopy terms: a. Focus: Focus is related to focal length and can be controlled with the focus knobs. The thickness of the cover glass on the specimen slide can also affect the ability to focus the image if it is too thick for the objective lens. The correct thickness is usually written on the slide of the objective lens. b. Resolution: Resolution is related to the numerical aperture of the objective lens – the higher the numerical aperture, the better the resolution; and the wavelength of light passing through the lens – the shorter the wavelength, the better the resolution. c. Contrast: Contrast is related to the illumination system and can be adjusted by changing the intensity of the light and diaphragm/pinhole aperture. Chemical stains applied to the specimen can also enhance contrast. C. Describe your observations from fresh yogurt slide you prepared in Part III. Under the 10X magnification, it was very hard to get a clear picture. Everything was covered in a gray matter and not very much was documented. Moving up a magnification, I was able to see some movement in between some cells. All the bacteria still looked unrecognizable and I still couldn’t determine the shape of the cells. With the oil immersion magnification, all the cells shape’s were irregular, but very short in size. D. Were there observable differences between your fresh yogurt slide and the prepared yogurt slide? If so, describe them. There was no movement at all in the prepared yogurt slide. The fresh slide that I had made had bacteria moving in one direction. E. Describe the four main bacterial shapes. Cocci – cell that is spherical or roughly spherical bacterium. Bacillus – a rod shaped bacterium Spirillum – rigid spiral structure Vibrio – any curved or spiral rodlike gram-negative bacterium F. What are the common arrangements of bacteria? Diplo – bacteria that can occur in pairs Strepto – bacteria that occurs in strands Staphylo bacteria that occurs in clusters G. Were you able to identify specific bacterial morphologies on either yogurt slide? If so, which types? I was able to see a lot of irregular shapes on both slides. These shapes were not very clear to make out. A lot of the cells on the prepared slide look mostly to be transparent, whereas the fresh yogurt slide was more dense. H. Describe the cells you were able to see in the blood smear. I was able to see tons of what seems to be erythrocytes. These red blood cells were clustered and almost stacked on top of one another. It looked like a life savor with nothing in the middle. They were circular in shape and pink in clolor. I. Are the cells you observed in your blood smear different than the bacterial cells you have observed? Why or why not? The red blood cells seemed much more different because they are more bigger in size and have their own distinct shape to it. Red blood cells need to be that shape in order to deliver oxygen throughout the body. J. What is the purpose of immersion oil? Why does it work? Immersion oil helps prevent light passing through the specimen and it also help us see image more magnified.