Research Paper on Micrococcus and Escherichia Coli
In this experiment, an Unknown microorganism, Micrococcus and Escherichia coli have been observed under different magnification through a compound light microscope.
The unknown microorganism that had been observed under 100x objective lens has a 1000× total magnification, it was spherical in shape and has a form of Staphylococci. Through the observation, the colour of the stained cell was pink as it is gram-negative. While Micrococcus have a 400×total magnification and were having sphere-shaped cells that forms in a cluster that looks like grape. Its stained cells presented in a purple colour which means that it is gram-positive. As for Escherichia coli, it was being observed under 40× total magnification and the cells were spherical in shape and were arranged by the combination of sphere-shaped (coccus) and rod-shaped cells(bacillus).
The purpose of adding immersion oil was to prevent the loss of light and to maintain the light direction as the oil was placed between the glass slide and the objective lens. Immersion oil can preserve light direction as it has the same refractive index as the specimen glass (Burke, 2020). The presence of immersion oil plays a big role as if without it will only produce an image with poor resolution and if the oil is not being used under high magnification. Compound light microscope are capable to distinguish certain cells and their internal structures. Which includes organelles such as nucleus, cytoplasm, cell membrane and the shape of the cells.
When the microscope was stored or carried, the low-power objective needs to be placed in position to prevent damage or scratch of the lens (Ford, 2019). The diaphragm can be regulated by twisting it clockwise or counterclockwise to close or open it. If the light barely reaches beyond the field of view, the diaphragm can be open (Microscope Club, 2022). For condenser, it can be regulated by bringing the condenser lens closer using the condenser knob and rotate the light intensity knob to adjust the light intensity. Resolution or the ability to distinguish fine details of a microscope can be increased by changing the objective lens from low power to high power. Other than that, adjusting the fine focus knob and using immersion oil can also help to increase the resolution (Owens, 2017).
There are some problems or difficulties with the usage of microscope and its magnification. The first problem is the image of the microbes would appear blur and out of focus. To solve this problem, adjust the course focus knob and fine focus knob to get a sharp image and have some practice to get more familiar with the microscope (Paul, 2021). The other problem that would affect the image was when starting with the highest power objective lens first to observe the microbes which will cause difficulties to view the specimen as it magnifies to a small area of the specimen. To solve this problem, starts with low power objective lens to observe the specimens before switching to a higher power objective lens.
