Objective(s): Our objective is to gain knowledge of the functions and operations of the microscope through observation of bacteria and blood slides that are available for this assignment. We are also learning to “see” and observe various bacteria and their shapes as well as live yogurt cultures, blood, plaque and cheek swab samples and their arrangements. We are to gain knowledge by observing blood and its cells so to be able to distinguish between blood cultures and bacteria specimens.
Procedure(s) : General procedures are as follows:
Gathering and setting up experiments, hands on operation of the microscope and its various lenses, manipulating specimens on and off the microscope and following and carrying out viewing instructions for slide, regular and oil immersion and various staining and wet mount techniques.
Observations/Results :
Sample
Observations
Part 1
Part 2
150x
600x
1500x (Oil Immersion)
Amoeba proteus
Appears to be oval with a tail-like end and solid as well as membrane layered cells. The cells appear to be fuzzy and not well defined
Appears to look like the sun with the inner cell having multiple textures. Anabaena
A paisley shaped cell with bubbles in the membrane with a hollow center cell Several spherical shapes with pink, yellow and hollow centers An oval shaped cell with yellow and red linings.
Ascaris Eggs
Dozens of eggs appear most look yellow some appear clear.
The eggs appear to be gell-like. Some are even folded.
I can see the outer ring of the cell along with tiny circles inside the cell. “e” slide
Appears to be an E with fuzzy outer layer
I can see a small part of the “E” and the fuzzy outline appears clear. I can see only grey with specks here and there.
Paramecium
Appear to be divided with nucleus centers.
I can see the division clearly and there appear to be small circles inside. I can see clearly the nucleus with surrounding fuzzy outer lining. Penicillium w/conidia
Appears to be fiberous with tiny speckles.
Appears to be clumps of pink and purple tiny spheres.
The tiny spheres appear to stick together to form strands.
Yeast
Appears to be several small spheres.
The spheres now appear to have dark and light color
The spheres appear to have a nucleus made of several smaller spheres. Yogurt bacteria
Appears to be dense with small specks of pockets
Appears to be dark and dense
Appears to be dense with foggy clouds of dense particles.
Sample
Observations
150X
600x
1500x
Ex 2:
Fresh Yogurt
Appears to be dense and have particulates in it.
Still appears dense. Do not see any of the particulates amounting to much. The density is apparent with no visible bacteria. I could not see the particles which I assumed were active yogurt cultures. Ex 3:
Blood Smear
There are many cells, mostly round.
The cells are larger and more separated. I can see them very clearly. I am seeing what appears to be the cell membrane and nucleus in many of the cells.
Amoeba Proteus
(150x)
(600x)
(1500x)
Anabaena
(150x)
(600x)
(1500x)
Paramecium
(150x)
(600x)
(1500x)
Penicillium with condia
(150x)
(600x)
(1500x)
Yeast
(150x)
(600x)
(1500x)
Yogurt Bacteria
(150x)
(600x)
(1500x)
Fresh Yogurt
N/A
(150x)
(600x)
(1500x)
Blood
(150x)
(600x)
(1500x)
Ascaris Eggs
(1500x)
Analysis and Interpretation:
Amoeba Proteus @ 150, 600 and 1,500X
In observing slide 150X it does not appear that this amoeba is in any final stages before splitting as the Amoeba Proteus does just before it reproduces. One can see in the 600X slide what appears to be the kontraktile Vakuole and the Zellkern (nucleus) more clearly. In the 1,500X slide we were able to see what appears to be the Nahrungsvakuole of the Amoeba Proteus. Reference: Amoeba Proteus figure retrieved from figure 3 of: Wilson, Edmund B. (1900) The cell in Development and Inheritance (second edition ed.), New York: The Macmillan Company
Penicillin conidia at 150X, 600X, 1500X and a figure of Penicillin conidia We could see in the 150X slide the fibrous branches of the Penicillin conidia sample slide that is demonstrated on the figure of Penicillin conidia. Our view and analysis of slide 600X and 1500X was of great discussion as we discussed the viewed sample appeared to be in the third stage of branching as is shown on our figure where there were many fibers present.
These photographs are of the yogart bacteria in order from 150X, 600X to 1,500X. We could see the denseity of the yogart in slide 150X and 600X, as well as what appeared to be live yogart cultures but in slide 1,500 the sample just appeared to be quiet with no movement yet still very dense.
Application
I have learned in this experiment that bacteria are alive and well in our mouth, on our skin and in our food. I work in a hospital as a CNA and out of my 13 patients that I have 5 will be on contact precautions for various contagious infectious diseases such as VRE, MRSA or HIV. What this means is that very specific infection control guidelines must be followed so as not to spread infection from patient to patient. The knowledge that I am gaining in this lab and from my chapters on bacteria help me to understand how disease is spread and what I can do to prevent its spread. I found an article on teaching nurses the importance of learning microbiology and it focused on infection control and the basic knowledge of microbiology: “While the factors discussed above cause practical difficulties in maintaining infection control standards, the author of a recent letter in Nursing Times believes that staff – particularly nurses – need better understanding of how infections spread if they are to combat them (Seewoodhary, 2004), and that this involves an understanding of microbiology” (Shuttleworth, 2004). The basic knowledge of microbiology that I am learning by viewing bacteria through the microscope will help me with Nursing as I practice effective infection control.
Reference:
Shuttleworth, A. (2004). Teaching nurses the importance of microbiology for infection control. Nursing times.net, 100(36), 56. Retrieved from http://www.nursingtimes.net/teaching-nurses-the-importance-of-microbiology-for-infection-control/204114.article#
Answers to Lab Questions
Exercise 1
1. Identify the following parts of the microscope and describe the function of each. A – eyepiece: transmits and magnifies the image from the objective lens to your eye. B – body: the upright microscope
C – nosepiece: a rotating mount that holds many objective lenses. D – objective lens: gathers light from the specimen.
E – stage: where the specimen rests.
F – aperture diaphragm control: placed in the light path to alter the amount of light reaching the condenser. Varying the amount of light alters the image contrast. G – light source: produces light.
H – coarse focus: brings the object into the focal plane of the objective lens. I – fine focus: 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 magnified image, even moving the specimen slightly can move parts of the image out of view.
L – base: supports the weight of all of the microscope parts.
2. Define the following microscopy terms, Focus, Resolution and Contrast: The focus is defined as the point at which the light from a lens comes together so you can see your sample clearly. Resolution is usually measured in nanometers and is the closest two objects can be before they are no longer detected as separate objects. Contrast is a part of the illumination system of the microscope and can be adjusted by changing the intensity of the light and the diaphragm/pinhole aperture.
3. What is the purpose of immersion oil? Why does it work? The purpose of immersion oil is to see the sample more clearly. The oil immersion lens uses immersion oil to capture some of the light that would otherwise be lost to scatter. Reducing scatter increases resolution(pg. 49, para. 1, Microbiology fundamentals)
Exercise 2
A. Describe your observations of the fresh yogurt slide: The fresh yogurt slide appeared dense and had particulate pieces floating about that I assume are live active cultures. B. Were there observable differences between your fresh yogurt slide and the prepared yogurt slide? If so, explain. I did not see any observable differences and this was peculiar to me. C. Describe the four main bacterial shapes: There are the bacillus which are rod shaped bacteria, and cocci which are spherical bacteria, they are the most common. The other three shapes are spheres, commas and spirals
D. What are the common arrangements of bacteria? Common arrangements of bacteria are diplo which are bacteria which occur in pairs, strepto which are bacteria which occur in strands, staphylo which are bacteria which occur in clusters and diplococcus which are bacteria that are round and found inhabiting yogart. E. Were you able to identify specific bacterial
morphologies on either yogurt slide? If so, which types? I know that I should have been able to see round diplococcus bacteria in the yogart culture but I could not really see them. In the 150X slide there appears to be particulates in the culture, could this be the diplococcus bacteria?
Exercise 3
A. Describe the cells you were able to see in the blood smear. Unlike the bacteria smears, the blood smear produced perfectly round cell shapes. In the 150X picture you can see hundreds of thousands of round cells and in the 600X picture you can see a few of the cells individually. B. Are the cells you observed in your blood smear different than the bacterial cells you have observed? Why or why not? Yes, they are different in shape as they are perfectly round. There is an obvious “look” to them as opposed to the fibrous or fuzzy bacteria.
