Bacterial Isolation Introduction There are approximately 10, named species of microbes. It is estimated that there are between 10, andmore unidentified species for every identified one.
Not only are there many types of bacteria, there are a lot of individual bacteria. A single spoonful of soil can have million individual bacteria. A scraping of your gums can yield 1 million bacteria per cm2 a cm2 is about the size of your little fingernail. Most of the currently known species of bacteria have been identified using traditional microbiological techniques such as the gram stain reaction, morphology, and metabolic reactions.
Bacteria rarely live alone but in communities with other bacteria. This is true both in the environment and in and on our bodies.
This class focuses on the role of bacteria in disease. Isolating a single bacterium species is the first step in identifying the bacteria possibly responsible for a disease process. The first requirement for physically isolating a bacterium is that it can be cultured in the laboratory.
This requires knowledge of optimal temperature for growth, optimal oxygen requirements, and optimal nutritional needs. We work with a very limited number of bacteria in this course. The bacteria we work with are also very easy to culture in the lab. Most bacteria are not this agreeable!
There are two main ways to isolate organisms. Streaking for isolation on an agar plate The pour plate method Streaking for isolation on an agar plate involves the successive dilution of organisms until you have the cells at a low enough density that single cells are physically isolated spatially to give rise to recognizable individual colonies.
In the pour plate method, you dilute your sample sufficiently before you add it to molten cooled agar and then pour this mixture in a dish. The isolated cells give rise to individual colonies growing in the agar itself. This technique can be a little tricky.
If the melted agar is too hot you kill all the bacteria. If the melted agar is too cool you end up with a big lump in your Petri dish. The streaking method yields individual colonies on the surface of the agar.
This technique is much faster and easier to master. Overview You will be given a broth sample containing three organisms, Staphylococcus xylosus, Serratia marsescens, and Escherichia. All three organisms readily grow aerobically on tryptic soy agar TSA.
It grows very rapidly at all temperatures into medium sized colonies. Your ability to isolate and see the three organisms on your plate is dependent on appropriate incubation conditions.
Your plates will be incubated at room temperature for 48 hrs. You should be able to identify the three organisms based on colony size and pigment. Materials 1 mixed-culture in tryptic soy broth TSB tube containing Staphylococcus xylosus, Serratia marsescens, and Escherichia.
The vast majority of our students have been most successful with the quadrant method of streaking which is described below. Label your plate with your name, date, section, and organism. Refer to the aseptic technique protocol. Be sure that you have adequately mixed your broth tube so the organisms are uniformly suspended in the broth.
Recap your TSB tube.
You can do the next part with your plate on the lab bench or holding it in your hand. You decide which works best. Lightly drag your loop back and forth across the surface of the agar.
Refer to Figure 1. The more you drag the more bacteria you deposit. The general idea is to decrease the bacterial concentration with each swipe.We performed a two-part experiment to gain a better understanding of bacteria through gram-staining.
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|LabReportIBGGroup LAB REPORT 6 (BACTERIAL DNA EXTRACTION)||None Such Island Gallery Introduction We performed a two-part experiment to gain a better understanding of bacteria through gram-staining. Gram staining is a differential staining method which results in the classification of two groups of bacteria, Gram-positive and Gram-negative.|
Gram staining is a differential staining method which results in the classification of two groups of bacteria, Gram-positive and Gram-negative. The premise of the Bacterial Isolation lab is a report of ampicillin resistant bacteria in poultry meat. You will visit the place of origination, a chicken farm, in hopes of identifying the bacteria strain.4/4(22).
The identification of bacteria is a careful and systematic process that uses many different techniques to narrow down the types of bacteria that are present in an unknown bacterial culture.
It produces benefits for many aspects of the research of microorganisms and helps physicians correctly treat patients. Experiment 2 Plasmid DNA Isolation, Restriction Digestion and Gel Electrophoresis Plasmid DNA isolation introduction: The application of molecular biology techniques Resuspend the bacterial pellet in µL of buffer Cell Resuspension Buffer.
LAB REPORT 6 (BACTERIAL DNA EXTRACTION) INTRODUCTION. DNA isolation is a process of purification of DNA from sample using a combination of physical and chemical methods.
DNA is extracted from human cells for a variety of reasons. With a pure sample of DNA we can test a newborn for a genetic disease, analyze forensic evidence, or study a gene. LAB Report #3 Introduction: In this lab we have focus on Isolation of bacteria from environment.
Microorganisms are found throughout the environment: in the air and water; on the surface of any object such as clothes, walls, furniture; in soil and dust; and on .