Microscopy Lab Report

It has been used for centuries to colour certain foods and fibres. More recently, the development of the chemical Sodium Hypochlorite, also known as household bleach, has been utilized to decolour materials. The reaction between the two is shown.

Gram positive bacteria is impenetrable to sanitizers because of its thick and well built plasma membrane which is thicker than most viruses and fungus cell’s membranes. This attribute gives great difficulty to alcohol antiseptics and is hard to destroy the proteins inside the cell because of the thick wall.

In order to start a stain, the microorganisms must be fixed to the microscope slide. This first step is called preparing a smear. Spread the specimen on a slide and let it air-dry. Once the specimen is dry it must then be heat fixed by waving the slide just one or two times over the flame. After this step is completed, the staining techniques begin. The Gram stain is considered a differential staining technique because it places bacteria into categories. The first step during the Gram staining technique is applying the primary stain, crystal violet, for twenty to sixty seconds. After this is completed, rinse with water and proceed to add the mordant stain, iodine, for one minute. The mordant

Confocal microscopy uses a laser that produces excitation light. This laser light reflects off of a dichroic mirror and then the laser light hits two mirrors that are mounted on motors. The mirrors then scan the laser light across the sample. Dye that is found in the sample then fluoresces (Weeks, 2003). Filamin was labeled with a red fluorescent label rhodamine (TRITC) and actin was labeled with the green fluorescent label fluoroscein (FITC) which was conjugated to the actin-binding fungal toxin phalloidin. The emitted light from the dyes passes back through the mirrors and passes through the dichroic mirror and is focuses into a pinhole. With confocal microscopy, a complete image of the sample is

The stain was added to enable the observation of chromosomes as it helped to make them stand out under the microscope.

Gram staining is a technique used to determine if the bacteria is Gram positive or Gram- negative. Gram staining procedure uses crystal violet stain, iodine moderator, alcohol decolorizer and safarin counter stain. In Gram- negative bacteria the primary stain will be washed out with the decolorizer and it will be stained with the counterstain. Whereas in Gram-positive bacteria the primary stain will not leave the cell wall. This difference comes from difference in the structure of the cell wall that retains the stain.

As we know bacteria comes in various classes and are distinguished by their shapes, chemical configuration, source of energy either sunlight or chemicals, nutritional requisites and biochemical actions.

Figure 3 identifies a cluster of tightly compacted onion cells with two distinct outlines surrounding the cell. The first visible outline is the cell wall and the second distinct outline is the cell’s plasma membrane. On account that the onion cell has not been stained, hence the nucleus and other organelles are not visible in this onion cell under this magnification.

There are three main types of bacteria.They can be determined and distinguished by their cell morphology. Cell morphology is the identification of the shape, structure, size of the cell and its form. It pertains to the shape of bacteria. For instance, Coccus (cocci) bacterium are spherical and generally round shaped. Bacillus bacterium are generally rod shaped and are a genus of gram positive bacteria. Finally, the third common type of bacterial morphology is the spirillum bacteria. Spirillum bacteria s generally a spiral shaped bacterium and are a genus of the Gram

In the medical field, certain bacteria need specific antibiotic treatments and to find out what class the bacteria belongs to (whether if it is gram negative or positive) the specimen would have to undergo differential (Gram) staining. Hans Christian Gram was the Danish bacteriologist behind the gram staining technique. His Gram stain technique led to the discovery that Typhus bacillus did not retain the stain. Another procedure like differential staining is called simple staining. The main difference with this procedure is its simplicity and use of just one dye while the differential staining is more complex, uses more staining and helps shows cellular components of the bacteria. There are 3 bacteria that will be in use for the Gram staining.

Gram staining-it is a technique used to differentiate between Gram-positive cells, which stain purple, and Gram-negative cells, which stain pink. The physical and chemical structures of these cells are different, allowing them to be identified by the used of different dyes. The first step is to color all the cells of the smear by using the basic dye crystal violet for 1 minute. Then iodine is used to bind the dye and make it less soluble, after it is rinse all cell remain

A coccus is a spherical-shaped bacterial cell while a rod is a rod-shaped bacterial cell (sometimes called a bacillus)

The flattening of the onion root tips allows the chromosomes of each individual cell to be observed. The hydrochloric acid added, plays a part in fragmenting the root tissues by weakening and removing the bonds between cells so that each cell will not be attached to the other cell, obstructing the observation. Toluidine Blue solution acts as a colorant, giving a blue colour to the chromosomes and so that it is more easily spotted

The students will duplicate cell diagram and will be able to recognize the structure and organelles of both plant and animal cells The students will also be able to describe

A small square of a red onion skin (membrane) was observed under a microscope at high power (X40) magnification. The observation showed a large number of onion cells. The structure of one onion cell had a general rectangular shape with a developed cell wall, which gives the rectangular shape to the cell and a cell membrane just beneath it.