LAB 1 : SHAHRUL EZZATI BT SHAHRUL AMIR -111416-

INTRODUCTION


The purpose of a microscope is to magnify a small object or to magnify the fine details of a larger object in order to examine minute specimens that cannot be seen by the naked eye.


Here are the important microscope parts...

Eyepiece: The lens the viewer looks through to see the specimen. The eyepiece contains a 10X or 15X power lens.

Diopter Adjustment: Useful as a means to change focus on one eyepiece so as to correct for any difference in vision between your two eyes.

Body tube (Head): The body tube connects the eyepiece to the objective lenses.

Arm: The arm connects the body tube to the base of the microscope.

Coarse adjustment: Brings the specimen into general focus.

Fine adjustment: Fine tunes the focus and increases the detail of the specimen.

Nosepiece: A rotating turret that houses the objective lenses. The viewer spins the nosepiece to select different objective lenses.

Objective lenses: One of the most important parts of a compound microscope, as they are the lenses closest to the specimen.

A standard microscope has three, four, or five objective lenses that range in power from 4X to 100X. When focusing the microscope, be careful that the objective lens doesn’t touch the slide, as it could break the slide and destroy the specimen.

Specimen or slide: The specimen is the object being examined. Most specimens are mounted on slides, flat rectangles of thin glass.

The specimen is placed on the glass and a cover slip is placed over the specimen. This allows the slide to be easily inserted or removed from the microscope. It also allows the specimen to be labeled, transported, and stored without damage.

Stage: The flat platform where the slide is placed.

Stage clips: Metal clips that hold the slide in place.

Stage height adjustment (Stage Control): These knobs move the stage left and right or up and down.

Aperture: The hole in the middle of the stage that allows light from the illuminator to reach the specimen.

On/off switch: This switch on the base of the microscope turns the illuminator off and on.

Illumination: The light source for a microscope. Older microscopes used mirrors to reflect light from an external source up through the bottom of the stage; however, most microscopes now use a low-voltage bulb.

Iris diaphragm: Adjusts the amount of light that reaches the specimen.

Condenser: Gathers and focuses light from the illuminator onto the specimen being viewed.

Base: The base supports the microscope and it’s where illuminator is located.

How does a microscope work?

A light microscope works very much like a refracting telescope, but with some minor differences. Let's briefly review how a telescope works.

A telescope must gather large amounts of light from a dim, distant object; therefore, it needs a large objective lens to gather as much light as possible and bring it to a bright focus. Because the objective lens is large, it brings the image of the object to a focus at some distance away, which is why telescopes are much longer than microscopes. The eyepiece of the telescope then magnifies that image as it brings it to your eye.

In contrast to a telescope, a microscope must gather light from a tiny area of a thin, well-illuminated specimen that is close-by. So the microscope does not need a large objective lens. Instead, the objective lens of a microscope is small and spherical, which means that it has a much shorter focal length on either side. It brings the image of the object into focus at a short distance within the microscope's tube. The image is then magnified by a second lens, called an ocular lens or eyepiece, as it is brought to your eye.

The other major difference between a telescope and a microscope is that a microscope has a light sourceand a condenser. The condenser is a lens system that focuses the light from the source onto a tiny, bright spot of the specimen, which is the same area that the objective lens examines.

Also unlike a telescope, which has a fixed objective lens and interchangeable eyepieces, microscopes typically have interchangeable objective lenses and fixed eyepieces. By changing the objective lenses (going from relatively flat, low-magnification objectives to rounder, high-magnification objectives), a microscope can bring increasingly smaller areas into view -- light gathering is not the primary task of a microscope's objective lens, as it is a telescope's.

OBJECTIVE

1. Learn how to use microscope correctly
2. To expose the student tne about the shape and activity of microorganism

RESULTS

1. Stained cells

penicillium spp.

DISCUSSION

    Penicillium spp. are widespread and are found in soil, decaying vegetation, and the air. Showing again how it is distinct from other species in this genus, Penicillium spp. is endemic specifically in Southeast Asia where it infects bamboo rats which serve as epidemiological markers and reservoirs for human infections. For Penicillium species, septate hyaline hyphae (1.5 to 5 µm in diameter), simple or branched conidiophores, metulae, phialides, and conidia are observed. Metulae are secondary branches that form on conidiophores. The metulae carry the flask-shaped phialides. The organization of the phialides at the tips of the conidiophores is very typical. They form brush-like clusters which are also referred to as "penicilli". The conidia are round, unicellular, and visualized as unbranching chains at the tips of the phialides. At 37°C, Penicillium spp. colonies are cream to slightly pink in color and glabrous to convoluted in texture.

    The second method which is wet mounts remains the most widely used method for identifying ova and cysts of parasites from stool specimens (Valentina & Lalitha, 2001). The classical technique described for the microscopic examination of parasites is the iodine mount method, which facilitates the differentiation and identification of parasites by characteristic morphological features and details of internal structures. The method is easy, less time-consuming and inexpensive, allowing direct visualization of parasitic ova and cyst morphology. The only disadvantage to this technique is that the preparation dries within a few minutes, rendering it unreadable.

    Saccharomyces cerevisiae is a species of yeast. It is perhaps the most useful yeast, having been instrumental to baking and brewing since ancient times. It is believed that it was originally isolated from the skin of grapes (one can see the yeast as a component of the thin white film on the skins of some dark-colored fruits such as plums; it exists among the waxes of the cuticle). It is one of the most intensively studied eukaryotic model organisms in molecular and cell biology, much like Escherichia coli as the model bacterium. It is the microorganism behind the most common type of fermentation. S. cerevisiae cells are round to ovoid, 5–10 micrometres in diameter. It reproduces by a division process known as budding.

    Lactobacillus fermentum is a Gram-positive species of bacterium in the genus Lactobacillus. It is associated with active dental caries lesions. It is also commonly found in fermenting animal and plant material. It has been found in sourdough. A few strains are considered probiotic or "friendly" bacteria in animals and at least one strain has been applied to treat urogenital infections in women. Some strains of lactobacilli formerly classified as Lactobacillus fermentum (such as RC-14) have since been reclassified as Lactobacillus reuteri. Commercialized strains of L. fermentum used as probiotics include PCC and ME-3. It is rod-shaped and straight. But under the certain conditions, they also can form spiral or coccobacillary. They are often found in pairs or chains of varying length.

CONCLUSION

   There are gram-positive and gram-negative bacteria. For gram-negative bacteria, they have thin cell wall and no peptidoglycan which is stain with pink colour.Example of this gram-negative bacteria is Penicillum spp. For gram-positive bacteria, they have thick cell wall of peptidoglycan which is stain with purple colour. Example of gram-positive bacteria is Lactobacilli fermentum. 

   Different type of bacteria had examine during the lab session. There are variety of shape,colour and size of bacteria had been examine using microscope. There are correct way to using a microscope to obtain the good results.

REFERENCE

1. http://www.doctorfungus.org/thefungi/penicillium.php
2. http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae
3. http://en.wikipedia.org/wiki/Lactobacillus_fermentum
4. http://jmm.sgmjournals.org/content/57/5/679.full

LAB 1 : ZHAMEIR SHAFIQ BIN MOHD ILIAS 113586

INTRODUCTION

A microscope is an example of instrument that we use to see microorganisms that are too small to be seen. Microorganisms is an organisms that cannot be seen by naked eyes. So, the microscope is used to examine this and in the same time, in order to study the sizes and shapes of living microorganisms, the wet mount methods is used. This method is used because it is quick,easy, does not require any special equipment and also enable us to determine if cells are motile. On the other hand, microscope was early made in 1590 in Netherlands. There are many types of microscopes that uses light to image the sample such as compound, digital, and fluorescence but most frequently microscope is used to view the microorganisms is light microscope. There are many parts in microscope that makes the microscope functioning :

1)     Eyepiece lens: lens that used to look the specimen. The power lens have 2 types that are 10x and 15x.

2)     Stage: platform that has hole at the mddle to allow light from illuminator to pass through the slide contain specimen and it is adjustable.

3)     Objective lenses: is used to magnify the specimen into particular lenses power in order to obtain the best view. There are 3 to 4 objectives lenses that are 4x, 10x, 40x, and 100x.

4)     Arm: to supports the eyepiece lens holder on the base.

5)     Illuminator: a steady light source that used in place of a mirror.

6)     Coarse and Fine focus: to adjust the stage to get the excellent image view.

7)     Condenser: to focus light from illuminator direct to the specimen.

8)     Nosepiece turret: holds two or more objective lenses and can be rotated to easily change power.

9)     Iris diaphragm: is used to vary the intensity and size of the cone of light that is projected upward into the slide.

How to use a microscope ?

1. When moving your microscope, always carry it with both hands. Grasp the arm with one hand and place the other hand under the base for support.

2. Turn the revolving nosepiece so that the lowest power objective lens is "clicked" into position.

3. The microscope slide should be prepared with a coverslip or cover glass over the specimen. This will help protect the objective lenses if they touch the slide. Place the microscope slide on the stage and fasten it with the stage clips. It is also can be push down on the back end of the stage clip to open it.

4. Look at the objective lens and the stage from the side and turn the coarse focus knob so that the objective lens moves downward or the stage, if it moves, goes upward. Move it as far as it will go without touching the side.

5. Now, look through the eyepiece and adjust the illuminator for the greatest amount of light.

6. Slowly turn the coarse adjustment so that the objective lens goes up from the slide. Continue until the image comes into focus. Use the fine adjustment, if available, for fine focusing.
7. Move the microscope slide around so that the image is in the center of the field of view and readjust the mirror, illuminator or diaphragm for the clearest image.
8. Now, you should be able to change to the next objective lenses with only minimal use of the focusing adjustment. Use the fine adjustment, if available. If you cannot focus on your specimen, repeat steps 4 through 7 with the higher power objective lens in place. Do not allow the objective lens to touch the slide.
9. The proper way to use a monocular microscope is to look through the eyepiece with one eye and keep the other eye open to helps avoid eye strain. If you have to close one eye when looking into the microscope, it is not a problem.  Remember, everything is upside down and backwards. When you move the slide to the right, the image goes to the left.
10. Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses.  
11. When finished, raise the tube or lower the stage, click the low power lens into position and remove the slide.
12.  Always keep your microscope covered when not in use.

Care of the microscope.

·         Everything on a good quality microscope is unbelievably expensive, so be careful.

·         Hold a microscope firmly by the stand, only. Never grab it by the eyepiece holder, for example.

·         Hold the plug (not the cable) when unplugging the illuminator.

·         Since bulbs are expensive, and have a limited life, turn the illuminator off when you are done.

·         Always make sure the stage and lenses are clean before putting away the microscope.

·         NEVER use a paper towel, a kimwipe, your shirt, or any material other than good quality lens tissue or a cotton swab (must be 100% natural cotton) to clean an optical surface. Be gentle! You may use an appropriate lens cleaner or distilled water to help remove dried material. Organic solvents may separate or damage the lens elements or coatings.

·         Cover the instrument with a dust jacket when not in use.

·         Focus smoothly; don't try to speed through the focusing process or force anything. For example if you encounter increased resistance when focusing then you've probably reached a limit and you are going in the wrong direction.

OBJECTIVE

·         Learn to use a simple bright-field microscope correctly.

·         To provide an experience in the use of microscope.

·         To illustrate the diversity of cells and microorganisms.

RESULTS

1) Stained cells

Penicillium spp.

Figure 1: 40x magnification

Figure 2 : 100x magnification

Figure 3 : 400x magnification

    2) Wet mount

Saccharomyces cerevisiae

Figure 4 : 1000x magnification

Lactobacillus fermentum

Figure 5 : 1000x magnification

DISCUSSION

Penicillum spp. is a type of multicellular species. It is a gram-negative bacteria because it has stain with pink colour. The filamentous structure can be seen under 40x magnification under the microscope. The characteristics of this Penicillum spp. are nutrition mycelium colorless, pale, or with distinctive colors. It has hyphae with the diaphragm which is the diaphragm are conidiophores, smooth or rough. Base without enough cells, the formation of enlargement is not top of the top capsule, the conidiophore after several branches will resulting in several rounds of symmetrical or asymmetrical small stems that are shaped like a broom. Conidia spherical, oval or short cylindrical, smooth or rough, when most of the growth of blue-green. A few species have closed the capsule shell.

Wet mount methods is made by several liquids but usually water,immersion oils and glycerols is used. Water is really needed to make them but for some wet mounts, immersion oils will be used. Immersion oils is used in order to see the tiny specimen that hardly can be seen under the microscope besides the living and moving specimen can also be observed.

First specimen for the wet mount methods is Saccharomyces cerevisiae. It is classifies in fungi kingdom. This is because it has acell wall made of chitin and it has no peptidoglycan on its cell walls.Saccharomyces cerevisiae are able to break down its food through both aerobic respiration and anaerobic fermentation.They get their energy from glucose. They can survive in an oxygen deficient environment for a period. They also able to have both sexual and asexual reproduction.In asexual reproduction, the haploid of the yeast under goes mitosis and form more haploid yeasts. Then, these haploid yeasts, one from each strain will fuse together to form cell.The nuclei of both cell will fuses together and now, they will form zygote. The  diploid cell can go through mitosis which called budding.Another four more zygotes or they can go under meiosis and from an ascus which will split into four ascospores.Then, these haploids can undergo germination.

The second specimen for the wet mount methods is Lactobacilli fermentum. It is rod-shaped and straight. But under the certain conditions, they also can form spiral or coccobacillary. They are often found in pairs or chains of varying length. Lactobacilli fermentum is a gram-positive bacteria. They are also classified as lactic acid bacteria, and derive almost all of their energy from the conversion of glucose to lactate during homolactic fermentation. In this process, 85-90% of the sugar utilized is converted to lactic acid. They generate ATP by nonoxidative substrate-level phosphorylation.

CONCLUSION

There are two types of bacteria that are gram-positive and gram-negative bacteria. For gram-positive bacteria, they have thick cell wall of peptidoglycan which is stain with purple colour. Example of gram-positive bacteria is Lactobacilli fermentum. For gram-negative bacteria, they have thin cell wall and no peptidoglycan which is stain with pink colour.Example of this gram-negative bacteria is Penicillum spp. .

This report has identified the correct way to view sample of microorganisms by using the microscope. Different species of microorganisms was observed under different magnification to examine the structure and size of microorganisms.

REFERENCE

http://en.wikipedia.org/wiki/Microscope

http://microbewiki.kenyon.edu/index.php/Lactobacillus

http://bioweb.uwlax.edu/bio203/s2007/nelson_andr/

http://en.wikipedia.org/wiki/Penicillium

LAB 1 MOHAMMAD SHAFIQ BIN ABDULLAH 113569

INTRODUCTION

Light microscopes, which we are using, use light to produce their images. Scanning light microscopes are called dissecting microscopes, and there are many kinds of light-transmission scopes, named for the way the light is delivered. Our lab has mostly bright field compound microscopes - specimens are seen against a bright background, and several (compound) magnifications can be chosen by rotating the objective lenses. The magnification of the objectives - commonly 4X, 10X, 40X, and 100X - are magnified again by the eyepiece or ocular lenses - usually 10X - so the total magnification for the different objectives are 40X (4x10), 100X (10x10), 400X (40x10), and 1000X (100x10).

 Microscope Handling

1. Carry the microscope with both hands, one on the arm and the other under the base of the microscope.
2. Go over to the microscope storage area and properly transport one microscope to your working area.
3. Then, pick up a pair of scissors, newsprint, a slide, and a cover slip.
4. Remove the dust cover and store it properly. Plug in the scope. Do not turn it on until told to do so.
5. Examine the microscope and give the function of each of the parts listed on the right side of the diagram.

eyepiece or ocular body tube fine adjustment knob nosepiece high power objective  low power objective diaphragm mirror (many   microscopes have a light instead) base coarse adjustment  arm stage clip  inclination joint

OBJECTIVE

Student should be able to:

1.      properly care for and confidently use microscope

2.      Identify the structure of microscope

3.      Use proper technique with oil immersion lens and wet mounts

RESULT

1)      Stained cell

FIGURE 1

 Penicillium spp

40x magnification

FIGURE 2

 Penicillium spp

100x magnification

FIGURE 3

 Penicillium spp

400x magnification

2)      Wet mount

FIGURE 4

Saccharomyces cerevisiae 

1000x magnification

FIGURE 5

Lactobacillus fermentum

1000x magnification

DISCUSSION

Gram staining (or Gram's method) is a method of differentiating bacterial species into two large groups (Gram-positive and Gram-negative).It is based on the chemical and physical properties of their cell walls. Primarily, it detects peptidoglycan, which is present in a thick layer in Gram positive bacteria.A Gram positive results in a purple/blue color while a Gram negative results in a pink/red color.The Gram stain is almost always the first step in the identification of a bacterial organism, and is the default stain performed by laboratories over a sample when no specific culture is referred.

Penicillium is a genus of ascomycetous fungi of major importance in the natural environment as well as food and drug production. Members of the genus produce penicillin, a molecule that is used as an antibiotic, which kills or stops the growth of certain kinds of bacteria inside the body. The thallus (mycelium) typically consists of a highly branched network of multinucleate, septate, usually colorless hyphae. Many-branched conidiophores sprout on the mycelia, bearing individually constricted conidiospores. The conidiospores are the main dispersal route of the fungi, and often are green in color.Sexual reproduction involves the production of ascospores, commencing with the fusion of an archegonium and an antheridium, with sharing of nuclei. The irregularly distributed asci contain eight unicellular ascospores each.Penicillium is a gram-negative.

Saccharomyces cerevisiae is a species of yeast. It is perhaps the most useful yeast, having been instrumental to baking and brewing since ancient times. It is believed that it was originally isolated from the skin of grapes (one can see the yeast as a component of the thin white film on the skins of some dark-colored fruits such as plums; it exists among the waxes of the cuticle). It is one of the most intensively studied eukaryotic model organisms in molecular and cell biology, much like Escherichia coli as the model bacterium. It is the microorganism behind the most common type of fermentation. S. cerevisiae cells are round to ovoid, 5–10 micrometres in diameter. It reproduces by a division process known as budding.Many proteins important in human biology were first discovered by studying their homologs in yeast; these proteins include cell cycle proteins, signaling proteins, and protein-processing enzymes. The petite mutation in S. cerevisiae is of particular interest.Saccharomyces cerevisiae is currently the only yeast cell that is known to have Berkeley bodies present, which are involved in particular secretory pathways.Antibodies against S. cerevisiae are found in 60–70% of patients with Crohn's disease and 10–15% of patients with ulcerative colitis.

Lactobacillus, also called Döderlein's bacillus, is a genus of Gram-positive facultative anaerobic or microaerophilic rod-shaped bacteria. They are a major part of the lactic acid bacteria group, named as such because most of its members convert lactose and other sugars to lactic acid. In humans they are present in the vagina and the gastrointestinal tract, where they are symbiotic and make up a small portion of the gut flora. They are usually benign, except in the mouth where they have been associated with cavities and tooth decay (dental caries). Many species are prominent in decaying plant material. The production of lactic acid makes its environment acidic, which inhibits the growth of some harmful bacteria. Several members of the genus have had their genome sequenced. Some Lactobacillus species are used for the production of yogurt, cheese, sauerkraut, pickles, beer, wine, cider, kimchi, cocoa, and other fermented foods, as well as animal feeds, such as silage. Sourdough bread is made using a "starter culture," which is a symbiotic culture of yeast and lactic acid bacteria growing in a water and flour medium. Lactobacilli, especially L. casei and L. brevis, are some of the most common beer spoilage organisms. The species operate by lowering the pH of the fermenting substance by creating the lactic acid, neutralising it to the desired extent.

CONCLUSION

Now we know how to handle microscope properly and other precaution that we need to take care  about. It to avoid us from taken damage from microscope and spoil it because microscope have a sensitive part.

Use an oil immersion lens when you have a fixed (dead - not moving) specimen that is no thicker than a few micrometers. Even then, use it only when the structures you wish to view are quite small - one or two micrometers in dimension. Oil immersion is essential for viewing individual bacteria or details of the striations of skeletal muscle. It is nearly impossible to view living, motile protists at a magnification of 1000x, except for the very smallest and slowest. A disadvantage of oil immersion viewing is that the oil must stay in contact, and oil is viscous. A wet mount must be very secure to use oil. Oil immersion lenses are used only with oil, and oil can't be used with dry lenses, such as your 400x lens. Lenses of high magnification must be brought very close to the specimen to focus and the focal plane is very shallow, so focusing can be difficult. Oil distorts images seen with dry lenses, so once you place oil on a slide it must be cleaned off thoroughly before using the high dry lens again. Oil on non-oil lenses will distort viewing and possibly damage the coatings.

To use an oil immersion lens, first focus on the area of specimen to be observed with the high dry (400x) lens. Place a drop of immersion oil on the cover slip over that area, and very carefully swing the oil immersion lens into place. Focus carefully, preferably by observing the lens itself while bringing it as close to the cover slip as possible, then focusing by moving the lens away from the specimen. When in focus the lens nearly touches the cover slip. The focal plane is so narrow that it is very easy to focus right past it. If you are focusing toward the specimen, you can drive the lens right into it.

In a wet mount, the specimen is placed in a drop of water or other liquid held between the slide and the cover slip by surface tension. This method is commonly used, for example, to view microscopic organisms that grow in pond water or other liquid media, especially when studying their movement and behavior. It is also used to examine physiological liquids like blood, urine, saliva, semen, and vaginal discharge. Care must be taken to exclude air bubbles that would interfere with the viewing and hamper the organisms' movements. For pathological and biological research, the specimen usually undergoes a complex histological preparation that may involve cutting it into very thin sections with a microtome, fixing it to prevent decay, removing any water contained in it, staining specific parts of it, and impregnating or infiltrating it with some transparent solid substance. As part of this process the specimen usually ends up firmly attached to the slide.

REFERENCES
            http://faculty.fmcc.suny.edu/mcdarby/Pages/Lab%20Exercises/MICINTRO.htm

http://www.ekcsk12.org/faculty/jbuckley/lelab/microscopeuselab.htm

http://en.wikipedia.org/wiki/Penicillium

http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae

http://en.wikipedia.org/wiki/Lactobacillus

http://en.wikipedia.org/wiki/Microscope_slide

Campbell Biology (9th Edition),Jane B. Reece (Author), Lisa A. Urry (Author), Michael L. Cain (Author),         Steven A. Wasserman (Author), Peter V. Minorsky (Author), Robert B. Jackson (Author),2011