Lab 1 Notebook and Worksheet Micro PDF

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Lab 1 Notebook and Worksheet 1) Title of Lab exercises (1 point) Brightfield Microscopy Techniques and Isolation of Microorganisms

2) Objectives of the lab exercises (4 points) In this lab we will learn about biosafety*and*lab*safety*rules,*the*brightfield+microscope+,+and+how+to+ observe+microorganisms+under+the+microscope+using+objectives+of+10x,+40x,+100x+magnification+We+will+also+ learn+how+to+apply+oil+immersion+and+how+to+isolate++microorganisms+from+various+natural+environments. 3) Procedures for lab exercises (10 points) Obtain a microscope and carry the microscope with two hands. Place it on the desk with the open part away from you. Next is to clean all the lenses only with lens paper and lens cleaner if necessary. Do not use paper towels or Kim wipes: they can scratch the lenses. Do not remove oculars or any other parts from the body of the microscope. Cut a lowercase e from a printed page. Prepare a wet mount as illustrated in Fig. 1. Place the glass slide on the stage of the microscope, secure it firmly and move the slide until the letter e is over the opening of the stage. With the low-power objective in the position, lower the tube until the tip of the objective is within 5 mm of the slide. Be sure that you lower the tube while looking at the microscope from the side. Look into the microscope and slowly raise the tube by turning the coarse adjustment knob counter-clockwise until the object comes into view. Once the object is in view, use the fine adjustment knob to focus the desired image. Open and close the diaphragm, and lower and raise the condenser, noting what effect these actions have on the appearance of the object being viewed. Usually, the microscope is used with the substage condenser in its topmost position. The diaphragm should be open and then closed until just a slight increase in contrast is observed. Draw a letter e under x4, x10, and x40 magnification or take pictures and insert them into this protocol. Fig. 1 Preparation of wet-mount slide. Add a drop of water to the slide; Place the specimen (letter e) in the water; Place the edge of a coverslip on the slide so that it touches the edge of the water; Slowly lower the coverslip to prevent forming and trapping air bubbles. Perform a wet mount of a yeast specimen using the steps shown in Fig.1. Observe yeast under the microscope using low power (10x) and high-dry (40x). Write down your observations, name of the yeast, and draw or take pictures. Use the oil immersion lens to examine the two types of prepared stained pathogenic bacteria provided. First locate the stained area with the low-power objective, then get the focus very sharp under high-dry, then move the revolving nosepiece until you are halfway between the high-dry and oil immersion objectives. Place a small drop of immersion oil in the center of the illuminated area on the slide. Continue revolving the nosepiece until the oil immersion objective clicks into place. The lens will now be immersed in oil. Sharpen the focus with the fine adjustment knob. Draw a few of the bacteria in the spaces provided. Write down the name of bacteria. After you are finished with the microscope, place the low-power objective in line with the ocular, clean the oil from the oil immersion lens with lens paper and lens cleaner, cover, and return the microscope to its proper storage place. + Isolation)Without)Selection)–)_Ubiquity)of)Bacteria+

Procedure)! Scrub+down+your+desktop+with+a+disinfectant.+Expose+your+TSA+plate+according+to+your+assignment+shown+in+ Table+1.+Label+the+bottom+of+your+plate+with+your+initials,+temperature+of+incubation,+and+the+date.+Moisten+a+ sterile+swab+by+immersing+it+into+a+tube+of+nutrient+broth+containing+BHI+and+expressing+most+of+the+broth+out+ of+it+by+pressing+the+swab+against+the+inside+wall+of+the+tube.+Sample+different+areas+with+the+cotton+swab+ according+to+your+assignment+shown+in+Table+2.+Once+the+assigned+area+has+been+sampled+with+the+swab,+snap+ the+end+off+the+cotton+swab,+and+immerse+the+swab+in+the+tube+of+BHI.+Label+the+tube+with+your+initial+

temperature+of+incubation,+and+the+date+Expose+the+blood+agar+plate+by+coughing+onto+it.+Label+the+bottom+of+ the+plate+with+your+initials_.+Be+sure+to+date+the+plate.+Incubate+the+plates+from+the+environment+at+25+C+for+5-7+ days.+37°C+plate+into+refrigerator+or+at+room+temperature+after+48+hours+and+observe+all+plates+at+the+same+ time+during+the+next+lab.++ +

4) Lab results with pictures or drawings (10 points) Picture of letter e at x4, x10, x40

Picture of yeast at x10, x40

Picture of the first pathogenic bacterium (Clostridium Tetani ) at X100

Archived from : microscope world Picture of the second pathogenic bacterium (Neisseria gonorrhoeae ) at x100

Archived from : https://phil.cdc.gov/details_linked.aspx?pid=2746

5) Lab summary and conclusion (5 points) we were successfully able to use a bright field microscope and practice proper techniques with it., doing so we were able to draw pictures of various objects and organisms. Lab 1 Worksheet 1) Describe the position of your hands when carrying the microscope to and from your laboratory bench (2 points). carry the microscope with two hands. One hand under the base and the other on the arm

2) Differentiate between the limit of resolution of the typical light microscope and that of the unaided human eye (3 points).

Resolution of the microscope depends on the wavelength of light being used and refraction of light; resolution on the eye depends on the ratio between the size of the pupil and the wavelength of light. the limit of resolution of the unaided human eye is about . 0.2 mm. for the typical light microscope, the limit is . 0.2 um. 3) (a) What two adjustments can be made to the condenser? (b) What effect do these adjustments have on the image? (3 points) -the condenser height can be changed ( up and down) and diaphragm (the amount of light) can be adjusted -illumination of the specimen is increased when the condenser is raised and the diaphragm is opened and if it is not adjusted properly it will not have a good resolution.

4) Why are condenser adjustments generally preferred over the use of the light intensity control? (2 points) condenser adjustments will increase illumination without affecting the bulb life

5) When using the oil immersion lens, what four procedures can be implemented to achieve the maximum resolution? (4 points) -using a layer of oil -using a blue filter over the light -raising the condenser to its highest point -opening the condenser diaphragm

6) Why is it advisable to start first with the low-power lens when viewing a slide? (2 points) Staring with the low power lens, which has a larger working distance, allows you to explore the slide to look for the specimen that is of interest to you and then progress up to the oil lens.

7) Why is it necessary to use oil in conjunction with the oil immersion lens and not with the other objectives? (2 points) the small working distance does not allow enough light to enter the lens. the oil directs more light into the lens by limiting the loss of light

8)What is the relationship between the working distance of an objective lens and its magnification power? (2 points) Working distance is the distance between an objective and the slide. The distance between the lens and the microscope slide decreases significantly as the magnification of the lens increases.

9) Match the lens (condenser, high-dry, low-power, ocular, or oil immersion) to its description. Choices may be used more than once (9 points). 1. This objective lens provides the highest magnification oil immersion 2. This objective lens provides the second highest magnification High-dry 3. This objective lens provides the lowest magnification low-power 4. This objective lens has the shortest working distance oil immersion 5.The coarse focus knob should be adjusted only when using this objective lens Low-power 6. This lens collects and focuses light from the lamp onto the specimen on the slide condenser 7. This lens, also known as eyepiece, often comes in pairs ocular 8. Diopter adjustments can be made to this lens ocular 9. A diaphragm is used to regulate light passing through this lens condenser 10) Answer the following true-false (T-F) questions: (5 points) 1. Acetone is the safest solvent for cleaning an objective lens ( F ). 2. Only lint-free, optically safe tissue should be used to wipe off microscope lenses ( T). 3. The total magnification capability of a light microscope is only limited by the magnifying power of the lens system ( F ). 4. The coarse focus knob can be used to adjust the focus when using any of the objective lenses ( F ). 5. Once focus is achieved at one magnification, a higher-power objective lens can be rotated into position without fear of striking the slide ( T ). 11) Describe how Saccharomyces cerevisiae look under the microscope with x40 (high-dry) objective (2 points). Looks rounded and can see them multiply and dividing. Looks like sand.

12) Which TWO pathogenic bacteria did you observe under oil immersion? Give a short description of these bacteria: (34 points - 17 for each bacterium) 1. Scientific name of the bacterium (2 points)

Clostridium tetani

Neisseria gonorrhoea

2. Shape and size (2 points). Clostridium tetani : rod-shaped and about 0.5 um in diameter and can be up to 2.5 um long

Neisseria gonorrhoea : Circular in shape (kidney bean ) and about 0.6 to 1 um in shape.

3. Find out in the literature, if the bacterium is Gram -positive (G (+)) of Gram-negative (G (-)) (2 points). Clostridium tetani : G +

Neisseria gonorrhoea : G -

4. Is it motile? (2 points) Clostridium tetani : Yes

Neisseria gonorrhoea : No

5.Is it a spore-forming bacterium? (2 points) Clostridium tetani : Yes

Neisseria gonorrhoea : No

6. What disease does it cause? Briefly describe signs and symptoms, the outcome, and possible treatment and prevention (7 points). Clostridium tetani : This bacterium is everywhere in the environment ,when you get a wound like a puncture wound from like a nail that is contaminated ,it causes the bacteria to release his spores into the body.Symptoms could be the fever and muscular skeletal symptoms such as muscle stiffness .Treatment can be done with antibiotics and antibodies called human tetanus immune globin (TIG). The most common prevention for this disease is getting the tetanus vaccine which is effective for 10 years.

Neisseria gonorrhoea : Causes Gonorrhea which is a sexual transmitted Disease. which causes painful urination swelling of the genital region abdominal pain and discharge from both the penis and the vagina.The disease this caused by sexual intercourse with an infected person.Prevention could be by knowing your sexual partner and their sexual partners if they have any.using protection while having sexual intercourse.And treatment can be done by using Antibiotics the CDC recommend an antibiotic injection called cerftriaxone with and oral antibiotic Zithromax .

Information about both the bacterium was gathered from last years microbiology slides, the textbook ,and the CDC website ....