...M2D1: Microscopy and Differential Staining 1. What are the advantages and disadvantages of the different types of light and electron microscopes discussed in Chapter 3 that are used to study microorganisms? Focus your response in terms of the following parameters: o Range of magnification o Resolving ability o Sample preparation o Possible states of sample (e.g. whole organism, part of, living, non-living, etc Compound Light microscopes magnification is 2000X. Resolution of about 0.2μm. Can only see very small specimens and specimens are stained. Darkfield – used to study live microorganisms that cannot be stained or staining distorts the image or they are invisible using the normal light microscope. Phase-Contrast – in living microorganisms, this scope allows you to see detailed internal structures, plus you do not have to fix or stain the microbes. Differential Interference Contrast (DIC) – instead of one beam of light, 2 beams are used. Image looks almost 3-dimensional and is brightly colored. Fluorescence – used mainly as a diagnostic technique. Stained with fluorochromes and viewed with an ultraviolent light. Confocal – makes 3-dimensional images using a computer. Able to see entire cells and their components. Two-Photon – living cells can be seen up to 1mm (1000um) deep in tissues. Can also track, in real time, the activity of cells. Scanning Acoustic – living cells that are attached to cancer cells, artery plaque and biofilms can be seen through...
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...Anna Anderson PTLW CSUEB July 2011 Activity 1.1.2 MICROBIOLOGIST * Microbiologist Microbiologists study microscopic bacteria, fungi, protists, and viruses. Many of these organisms cause disease (pathogens) and many can provide useful products such as penicillin (antibiotic). * Education and/or Training Required In order to work in this field you must have at least an undergraduate degree in microbiology. Further training with a Masters or Doctorate would be required to do anything other than entry level positions. Excellent microscopy skills and training in aseptic techniques are a must. * Responsibilities and Daily Activities This job requires a strong academic background with a lot of math, chemistry, and biology. Computer and lab skills are essential. Microbiologists grow cultures of bacteria (and other organisms) in medium for study. Using aseptic technique, they grow cultures to measure and calculate the rate of growth and how it grows. They learn what can and cannot kill their organisms and if it is a pathogen, they study ways to stop or slow its growth. In the lab, they work with microscopes, grow cultures, measure the rate of growth, and perform experiments with these organisms. Lab safety is very important in their work. They would NEVER eat or drink in the lab because this could cause contamination or could infect the food they are eating. * Salary Range Microbiologists can work in the academic community, industry or government...
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...Unknown Laboratory Report Sarah Mansfield Biology 203 Professor Lana November 19, 2014 INTRODUCTION Microorganisms are the earliest forms of life and most have thrived since the early birth of the planet. They have evolved into many different forms of life such as animals, humans, and plants. While some microorganisms impact life in a positive way by sustaining life, others cause disease and even death (Nester, et al. 2012). Prokaryotes are one of the earliest organisms to exist, and many of these organisms can thrive in conditions far worse than other living things. For example, they can tolerate extreme temperatures, acidic, or alkaline environments (Foster 1996). Prokaryotic cells do...
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...Introduction Morphological, staining, cultural and biochemical data on the characteristics of different microorganisms was gathered. This gained information can be used to identify bacteria. A scientist by the name of David Bergey was the first person who proposed the system of bacterial classification in which bacteria are grouped according to Gram reaction, metabolism, and morphology. The first edition of Bergey’s Manual of Systematic Bacteriology was published in 1984. This book can be used to identify a microorganism. The purpose of this experiment is to identify an unknown bacteria using the skills learned in microbiology laboratory this semester. Materials and Methods This experiment was conducted at Louisiana State University in Shreveport...
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...Diagnosis of an Infected Patient Infection is the invasion and growth of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body. A prokaryotic cell is a simple cell that does not have a nucleus. One of the most common types of prokaryotic cells is a bacterium. Bacteria are differentiated by many factors including shape, chemical composition, nutritional requirements, biochemical activities, and sources of energy (Tortora 76). A patient with an infection in the upper respiratory system will need to have a sputum sample sent to the lab for further evaluation to determine the cause in order to accurately treat the infection. While many microorganisms can be the cause of infection, this essay will focus on the following genera: Bacillus, Escherichia, and Mycoplasma as the cause of the patient’s infection. Bacillus is a rod-shaped, endospore-forming, facultatively anaerobic and gram-positive bacterium (Tortora G2). The gram stain is fundamental to identify the characteristics of bacteria as this process differentiates organisms according to the cell wall structure. Gram-positive cells have a thick cell wall layer and will stain blue to purple. The Gram stain process requires four steps which include applying a primary stain, usually crystal violet, to a heat-fixed smear, then adding a mordant, usually Iodine, followed by rapid decolorization with alcohol or acetone and finally counterstaining with safranin (Hussey). At...
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...Process and Techniques of Finding Unknown J Abstract: As part of a focal study within Microbiology, many scientists have endeavored to identify the many species and types of microbes found in different environments. In an effort to categorize, understand and distinguish one microbe from another, scientists developed tests to show unique characteristics of microbes. This experiment enlists these tests, such as PCR, Simple and Gram staining, anaerobic growth tests, IMViC, Catalase, Oxidase, selective and differential media to identify an unknown microorganism. The Unknown organism studied was labeled “J” and found to be a gram negative, rod shaped bacteria that does not produce endospores. The selective and differential agars produced no growth on the MSA agar plate showing that the bacteria did not favor a salty environment of the Mannitol salts and showed an acidic by product in the selective and differential media of MacConkey’s Agar. The bacteria showed to metabolize sugars but did not produce any gaseous byproducts. After 16s rRNA was processed and run through a PCR, electricphoresis was used to run the RNA out on a gel in order to sequence the RNA which was then compared in a database. Furthermore, the Unknown J did not produce or metabolize starch. The bacteria did not react with the Citrate, KEY oxidase. When compared to other known bacteria tested, unknown J proved to be Escherichia coli. Introduction: Identifying bacterial causes for certain diseases that have...
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...or Mycoplama, I would start ruling them out one by one. I would start with Bacillus. They are rod shaped bacterium which form endospores. Their movement is propelled by flagella. Bacilli are gram positive, but because if forms endospores, I would do the Endospore staining. Endospores are resistant to stain and relatively uncommon in bacterial cells. You start with a heat fixed smear. Fixing a slide kills the microorganism. A thin film of the microorganism is put on the slid and allowed to dry. Once dried, it is then fixed by either being passed through the flame of a Bunson burner several times or covered with methyl alcohol for 1 minute. Malachite green is applied and the smear is heated to steaming for 5 minutes, helping the stain penetrate the endospore wall. It is then washed with water for 30 seconds. This removes the stain from the cell except for the endospore wall. Safranin is applied as a counterstain to stain portions of the cell other than the endospore. In the smear, the endospores appear green with the rest of the cell red or pink. If there no endospores in the smear, it would eliminate bacillus as a contributing factor. Escherichia, commonly called E-coli, are also rod shaped microorganisms, and are gram negative. A gram stain is a differential stain developed Danish bacteriologist Hans Christian Gram. You start with a heat fixed smear using the procedure stated above. After they are fixed, it is then covered with crystal violet (or basic purple dye). After...
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...distinguish them. There are also staining processes that can identify each. Let’s get started. The genera Bacillus is a gram positive rod shaped bacterium. When viewed under a microscope Bacillus can be seen as a single organism or in chains. It forms endospores that are resistant to heat, cold, radiation and disinfectants. Bacillus is also aerobic, it needs oxygen to grow. Bacillus can be the cause of infections including abcesses, wound, burn and ear infections, endocardistist, meningitis, ophthalmitis, osteomyelitis, peritonitis and respiratory and urinart tract infections. The genera Escherichia is a gram-negative rod shaped bacterium. It does not form endospores. They are anerobic and can survive with or without oxygen. Escherichia can normally be found in the lower intestines. This can be the cause of gastroenteritis and urinary tract infections. The genera Mycoplasma are also rod shaped, like Bacillus and Escherichia. Mycoplasma lack a cell wall which makes staining difficult. It is also so small it makes it undetectable with a normal light microscope. This can be the cause of lung infections and urogenital infections. Infections caused by Mycoplasma are not easily treated by antibiotics. A way to distinguish these genera is by staining. This is a procedure developed by Hans Christian Joachim Graham, a Danish bacteriologistis. This process became known as Gram’s stain or the Gram stain. Gram staining is the coloring of microorganisms with dye so certain structures...
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...INTRODUCTION There are many reasons for knowing the identity of microorganisms. The reasons range from the knowing the causative agent of a disease in a patient, so as to know how it can be treated, to knowing the correct microorganism to be used for making certain foods or antibiotics. This study was done by applying all the methods that have been learned so far in the microbiology laboratory class for the identification of an unknown bacterium. MEDIA LIST Unknown Bacterium #5 Mannitol Salt Agar Plate DNA Agar Plate Blood Agar Plate RESULTS/ DATA The Unknown #5 had the following morphology after Gram staining and observed under a brightfiled microscope: purple color, spherical shape and clustered like grape. After determining that it was a Gram positive staphylococcus, it was inoculated on a MSA plate, Blood Agar, DNA agar and Catalase test was also performed to help figure out the staphylococcus type. The Table below lists all of the biochemical tests, their purpose and results. TEST PURPOSE REAGENTS OBSERVATIONS RESULTS Gram Stain To determine the Gram reaction of the bacterium Crystal violet, Iodine, Alcohol, Safranin Purple grape cluster arrangement cocci Gram Positive coccus Mannitol Salt Agar To determine the if the bacterium can tolerate high saline levels and grow If the bacterium can ferment mannitol None There was a full growth and the mannitol turned to yellow (acidic) Positive Blood Agar To determine if the bacterium can hemolysis...
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...Diagnosis of an Infected Patient: Microbiology Paper BIO 212 Professor Fazely January 18, 2015 Professor Fazely Bio 212 18 January 2015 Diagnosis of an Infected Patient After collecting a sputum sample from a patient that is suspected or may be infected with a bacterium from one of the following genera: Escherichia, Mycoplasma or Bacillus; Each bacteria listed should be isolated by utilizing each of the various staining techniques. The best staining techniques to use is the Gram stain or the Acid- fast stain due to the fact that they both will provide a lot of information in detail regarding the bacteria being studied. It is very important to be observant of how each bacterium obtained reacts to each stain, and how the results obtained will lead us in a developing diagnosis. The first technique being used is the Gram stain. Gram stain is probably one of the most common used staining procedures used in the field of microbiology. It is one of the differential stains that are used to characterize bacteria in one of the two groups: either gram positive or gram negative bacteria. Bacteria prepared for the Gram stain is a heated fixed smear that is covered with a crystal violet. Because the purple stain impart its color to all cells. After a short period of time, the purple dye is then washed off, and the smear is then covered with iodine, a mordant. When the iodine is then washed off, both the gram-positive and gram-negative bacteria appear dark violet in color or...
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...You are given a sputum sample from a patient that may be infected with a bacterium from one of the following genera: Bacillus, Escherichia, or Mycoplasma. In a Microsoft Word document, describe the important anatomical differences among these three genera (i.e., those features that could be used to differentiate among them) and the staining protocols you would use to identify which genera is causing the patient’s infection. When discussing each staining protocol, it is important not only to mention the steps involved, but also how each step and each protocol would identify or eliminate each of these genera as a suspect. You may refer to other scientific resources, but they should be in addition to and not in place of the Module 2 resources. Bacillus: Rod Shaped Bacteria, plural bacilli, Divide only across their short axis, most appear in single rods. Diplocacilli appear in pairs after divison, and streptobacilli occur in chains. Some bacilli look like straws, others are tapered and look like cigars and some are oval and look similar to cocci so they are called coccobacilli. Genera Bacillus contains bacteria such as Bacillus anthracis the bacteria that causes anthrax. Bacillus cells often form long, twisted chains of cells. Gram POSITIVE, can be aerobic or anaerobic. Prokaryotes, Has a cell wall Mycoplasma: Lack a cell wall Unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis. May be parasitic...
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...Biochemical tests are often used to determine the identity of bacteria and differentiate between its species. There are numerous types of tests meant to detect key characteristics such as morphology, stain, motility, fermentation pathways used, oxygen requirements, enzymes present, and redox tests used. By conducting these tests with aseptic techniques, one can usually narrow down an unknown bacterium to its family; with the help of dichotomous keys and Bergey’s Manual of Determinative Bacteriology, particular genus and species can be identified. The first tests commonly conducted on a bacterium also give the broadest results. Initial tests employ differential staining and normally include gram, capsule, and endospore stains. All three indicate...
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...Diagnosis of an Infected Patient: Microbiology Paper Bio 212 18 January 2015 Diagnosis of an Infected Patient After collecting a sputum sample from a patient that is suspected or may be infected with a bacterium from one of the following genera: Escherichia, Mycoplasma or Bacillus; Each bacteria listed should be isolated by utilizing each of the various staining techniques. The best staining techniques to use is the Gram stain or the Acid- fast stain due to the fact that they both will provide a lot of information in detail regarding the bacteria being studied. It is very important to be observant of how each bacterium obtained reacts to each stain, and how the results obtained will lead us in a developing diagnosis. The first technique being used is the Gram stain. Gram stain is probably one of the most common used staining procedures used in the field of microbiology. It is one of the differential stains that are used to characterize bacteria in one of the two groups: either gram positive or gram negative bacteria. Bacteria prepared for the Gram stain is a heated fixed smear that is covered with a crystal violet. Because the purple stain impart its color to all cells. After a short period of time, the purple dye is then washed off, and the smear is then covered with iodine, a mordant. When the iodine is then washed off, both the gram-positive and gram-negative bacteria appear dark violet in color or purple. The next, process is the slide is then washed with alcohol...
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...Name ___________________________________________(5 pts.) Chap 3 study Questions - You will learn and understand more if you complete these questions within 1 -2 days after lecture! Must use textbook or think it through yourself to answer some questions. What is the range of individual cell length in micrometers? 1) What do the following abbreviations stand for? m = mm= nm = 2) How many micrometers in a millimeter? How many millimeters in a meter? How many nanometers in a micrometer? To convert from one unit of measure to another, use an equivalency statement: Starting units (equivalency statement) = ending units 1) write the starting units with number 2) write the ending units 3) For the equivalency statement, put the ending units on top and the starting units at the bottom as shown below. This way the starting units cancel out and you are left with the ending units. Starting units (ending units/starting units) = ending units 4) Ask yourself which is the smaller unit: starting or ending? How many of the smaller units make up the larger unit? The unit that is smaller will be 1000 or 100 etc. The unit that is bigger will be 1. 5) Multiply to determine answer. Example: 6.8 m == ? nm Step 1 &2: 6.8 m (equivalency statement) = ____ nm Step 3: 6.8 m ( nm ) = _____ nm m Step 4: 6.8 m ( 1000 nm ) = _____ nm 1 m Step 5: 6800 nm 3) Convert the following (SHOW YOUR WORK to receive credit...
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...INTRODUCTIONS: Microorganisms are both beneficial and harmful. These microorganisms are important to humans because they play a role in the ecology of life, by decomposing wastes, both natural and man-made, such as creating nitrogen fertilizer at the root zones of certain crops. Other several pathogens that can cause serious harm, even immediate death due to the diseases or disease causing products they produce. Overall, microorganisms play an important role in life. The purpose of this study was to identify the unknown bacterium using biochemical tests and various methods that had been learned from previous the microbiology laboratory class. Identifying the unknown bacterium was determined by separating and differentiating possible bacteria based on specific biochemical characteristics. The differential tests used to identify the unknown cultures were Gram staining, oxidase, indole test, urea test, and casein test. MATERIALS AND METHODS: The unknown bacteria were given out by the lab instructor. Each student chose their own unknown bacteria according to the number. All methods have been practiced to ensure proper procedure identifying bacteria have been applied to this unknown. Procedures were followed as stated in the course laboratory manual provided by the instructor, unless otherwise noted. Each test performed identified was used to determine the specifics and identify the unknown bacterium. All of the following tests were performed on this unknown on February 09...
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