experiment 4: Microscopic examination of stained cell preparation and experiment 5: Microscopic examination of living microorganisms using a Hanging-Drop Preparation or a Wet Mount
Assalamualaikum and good morning everyone..... how are you guys?.😃😃😃.. so now Im going to share with you about my experience when I did my forth anf fifth experiment which are forth experiment about Microscopic examination of stained cell preparations and fifth experiment about Microscopic examination of living microorganisms using a Hanging-drop preparation or a Wet mount. First and foremost, after I was entered to the class, DR Adelene taught about the parts of microscope, different types of microscopes, the function of each parts of microscopes. DR also talked about the magnifications, resolving power or resolution and so on. The experiment that we did this week are more interesting than last week because we saw microorganisms under microscope.😁😁😁 Mr Hussain also taught us how to clean the objective lens, how to hold the microscope and gave some demo. For the fifth experiment, Mr Zainuddin was explained about the experiment and taught us how to do the experiment. For an example, how to prepare the slides. Now, Im going share the informations about this two experiments.
Experiment 4: Microscopic Examination of Stained Cell Preparations
Microscopy refers to the practice that involves the use of a microscope for the purpose of observing smallscale structure that cannot be viewed using the naked eyes and often cell staining necessary as structure s are difficult to discern due to insufficient contrast. Cell staining is a technique used for the main purpose of increasing contrast through changing the color of the parts of the structure being observed thus allowing for a clearer view. There are a variety of microscopic stain that can used in microscopy.
Components of the microscopic
Stage is a fixed platform with an opening in the center allows the passage of light from an illuminating source below to the lens system above the stage.
Illumination is the light source is positioned in the base of the instrument. Some have it built in other reversible mirror of one side flat other concave. External light is placed in front of the mirror.
Abbe Condenser is the component is found directly under the stage and contains two sets of lenses that collect and concentrate light as it p[asses upward from the light source into the lens systems.
Body tube is in above the stage and attached to the arm of the microscope.This structure houses the lens system that magnifies the specimen. The upper end of the tube contains the ocular or eyepiece lens. The lower portion consists of a movable nosepiece containing the objective lenses. Rotation of the nosepiece positions objectives above the stage opening. The body tube may be raised or lowered with the aid of coarse-adjustment knob and fine-adjustment knob that are located above or below the stage.
Theoretical principles of the microscopy
Magnification is the enlargement of a specimen is the function of a two-lens system.Thr ocular lens is found in the eyepiece, and the objective lens is situated in a revolving nosepiece. These lenses are separated by the body tube. The objective lens is nearer the specimen and magnifies it, producing the real image that is projected up into the focal plane and then magnified by the ocular lens to produce the final image. Resolving Power or Resolution is the how far apart two adjacent objects must be before a given lens shows them as discrete entities, this power of the lens dependent on the wavelength of light used and numerical aperture. The shorter the wavelength, the greater the resolving power of the lens. Refractive lens is the bending power of the light passing through air from the glass slide to the objective lens. Illumination is most common light source using tungsten lamp, light is passing through the condenser beneath stage.
Staphylococcus aureus before oil immersion
Saccharomyces cerevisiae before oil immersion
Bacillus subtilis before oil immersion
Experiment 5: Microscopic Examination of Living Microorganisms Using a Hanging-Drop Preparation or a Wet Mount
The simplest method for examining living microorganisms is to suspend them in a fluid (water, saline, or broth) and prepare either a “hanging drop” or a simple “wet mount..”The slide for a hanging drop is ground with a concave well in the center; the cover glass holds a drop of the suspension. When the cover glass is inverted over the well of the slide, the drop hangs from the glass in the hollow concavity of the slide. Microscopic study of such a wet preparation can provide useful information. Primarily, the method is used to determine whether or not an organism is motile, but it also permits an undistorted view of natural patterns of cell groupings individual cell shape. Hanging-drop preparations can be observed for a fairly long time, because the drop does not dry up quickly. Wet-mounted preparations are used primarily to detect microbial motility rapidly. The fluid film is thinner than that of hanging-drop preparations and therefore the preparation tends to dry up more quickly, even when sealed. Although the hanging drop is the classical method for viewing unstained microorganisms, the wet mount is easier to perform and usually provides sufficient information. The preparations microscopically for differences in the sizes and shapes of the cells, as well as for motility, a self-directed movement. It is essential to differentiate between actual motility and Brownian movement, a vibratory movement of the cells due to their bombardment by the water molecules in the suspension. Hanging-drop preparations and wet mounts make the movement of microorganisms easier to see because they slow down the movement of the water molecules.
Hay infussion
Experiment 4: Microscopic Examination of Stained Cell Preparations
Microscopy refers to the practice that involves the use of a microscope for the purpose of observing smallscale structure that cannot be viewed using the naked eyes and often cell staining necessary as structure s are difficult to discern due to insufficient contrast. Cell staining is a technique used for the main purpose of increasing contrast through changing the color of the parts of the structure being observed thus allowing for a clearer view. There are a variety of microscopic stain that can used in microscopy.
Components of the microscopic
Stage is a fixed platform with an opening in the center allows the passage of light from an illuminating source below to the lens system above the stage.
Illumination is the light source is positioned in the base of the instrument. Some have it built in other reversible mirror of one side flat other concave. External light is placed in front of the mirror.
Abbe Condenser is the component is found directly under the stage and contains two sets of lenses that collect and concentrate light as it p[asses upward from the light source into the lens systems.
Body tube is in above the stage and attached to the arm of the microscope.This structure houses the lens system that magnifies the specimen. The upper end of the tube contains the ocular or eyepiece lens. The lower portion consists of a movable nosepiece containing the objective lenses. Rotation of the nosepiece positions objectives above the stage opening. The body tube may be raised or lowered with the aid of coarse-adjustment knob and fine-adjustment knob that are located above or below the stage.
Theoretical principles of the microscopy
Magnification is the enlargement of a specimen is the function of a two-lens system.Thr ocular lens is found in the eyepiece, and the objective lens is situated in a revolving nosepiece. These lenses are separated by the body tube. The objective lens is nearer the specimen and magnifies it, producing the real image that is projected up into the focal plane and then magnified by the ocular lens to produce the final image. Resolving Power or Resolution is the how far apart two adjacent objects must be before a given lens shows them as discrete entities, this power of the lens dependent on the wavelength of light used and numerical aperture. The shorter the wavelength, the greater the resolving power of the lens. Refractive lens is the bending power of the light passing through air from the glass slide to the objective lens. Illumination is most common light source using tungsten lamp, light is passing through the condenser beneath stage.
Staphylococcus aureus before oil immersion
Staphylococcus aureus after oil immersion
Saccharomyces cerevisiae before oil immersion
Saccharomyces cerevisiae after oil immersion
Bacillus subtilis before oil immersion
Bacillus cereus before oil immersion
Bacillus cereus after oil immersion
Blood before oil immersion
Blood before oil immersion
Experiment 5: Microscopic Examination of Living Microorganisms Using a Hanging-Drop Preparation or a Wet Mount
The simplest method for examining living microorganisms is to suspend them in a fluid (water, saline, or broth) and prepare either a “hanging drop” or a simple “wet mount..”The slide for a hanging drop is ground with a concave well in the center; the cover glass holds a drop of the suspension. When the cover glass is inverted over the well of the slide, the drop hangs from the glass in the hollow concavity of the slide. Microscopic study of such a wet preparation can provide useful information. Primarily, the method is used to determine whether or not an organism is motile, but it also permits an undistorted view of natural patterns of cell groupings individual cell shape. Hanging-drop preparations can be observed for a fairly long time, because the drop does not dry up quickly. Wet-mounted preparations are used primarily to detect microbial motility rapidly. The fluid film is thinner than that of hanging-drop preparations and therefore the preparation tends to dry up more quickly, even when sealed. Although the hanging drop is the classical method for viewing unstained microorganisms, the wet mount is easier to perform and usually provides sufficient information. The preparations microscopically for differences in the sizes and shapes of the cells, as well as for motility, a self-directed movement. It is essential to differentiate between actual motility and Brownian movement, a vibratory movement of the cells due to their bombardment by the water molecules in the suspension. Hanging-drop preparations and wet mounts make the movement of microorganisms easier to see because they slow down the movement of the water molecules.
Hay infussion
Staphylococcus aureus
Proteus vulgaris
Bacillus cereus
Pseudomonas aeruginosa
environment
pond water
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