Exercise 1 Cover EXERCISE #1 MICROSCOPY,BACTERIAL ISOLATION AND STAINING. Exercisel FIRST SESSION Exercise2 FOCI:Aseptic Technique,Staining,Microscopic Observation of Bacteria Exercise3 and Bacterial Isolation Using Streak Plate Method. Exercise4 A.Aseptic Technique and Isolation of Bacteria colonies Exercise5 Man harbors a wide variety of microorganisms on the skin and in the oral cavity,nasopharynx and intestinal tract.In all these areas of the body,many Exercise6 different kinds of bacteria exist together.Thus,if they are to be studied individually,each species must be isolated and then sub-cultured to obtain a Exercise7 pure culture.This is particularly true in the study of disease where it is Clinical necessary to isolate and identify the specific etiologic agent.Each of the case studies students is to develop lab skills that are collectively referred to as aseptic technique.This concept must be consistently kept in mind when handling Suggestions bacterial cultures because the careless student will contaminate everything including the pure cultures of bacteria provided for the study of general Hit Counter bacteriology.Without pure cultures this study becomes an effort in futility Aseptic technique will be demonstrated by the lab instructor and the studen should become quite familiar with the procedure to aseptically transfer bacteria from pure cultures. In general,pure cultures of isolated bacterial colonies are best obtained by using solid media and streak plates are primarily used for this purpose. y Each student will receive a tryptic soy agar plate and a tube of broth containing a mixture of bac eria.The "fou -way "method will be used to streak the plate.This will be demonstrated by the instructor and is described below. 1.Never remove the top of the plate but lift the lid just high enough to make complete strokes 2.Place a loop of organisms on one edge of the agar(area 1)and then streak back and forth,overlapping the streaks until you have covered about one fourth of the plate. 3.Flame the loop before proceeding to each of the other steps 4.Turn the plate approximately 90 and start streaking from one corner of the streaked area 1 and cover about one fourth of the surface(area 2).Turn again and streak surface area 3 by overlapping area 2,as shown below. Repeat this method and streak the surface of area 4 but do not run the final streaks back into any of the previous areas.You have now spread the file://C/WINDOWS/Desktop/clown/Microb Lab Web 2001/Exercise1/exercise1b.htm(1 of6)[8/3/00 9:54 PM Cover Exercise1 Exercise2 Exercise3 Exercise4 Exercise5 Exercise6 Exercise7 Clinical case studies Suggestions Hit Counter EXERCISE #1 MICROSCOPY, BACTERIAL ISOLATION AND STAINING. FIRST SESSION FOCI: Aseptic Technique, Staining, Microscopic Observation of Bacteria, and Bacterial Isolation Using Streak Plate Method. A. Aseptic Technique and Isolation of Bacteria colonies Man harbors a wide variety of microorganisms on the skin and in the oral cavity, nasopharynx and intestinal tract. In all these areas of the body, many different kinds of bacteria exist together. Thus, if they are to be studied individually, each species must be isolated and then sub-cultured to obtain a pure culture. This is particularly true in the study of disease where it is necessary to isolate and identify the specific etiologic agent. Each of the students is to develop lab skills that are collectively referred to as aseptic technique. This concept must be consistently kept in mind when handling bacterial cultures because the careless student will contaminate everything, including the pure cultures of bacteria provided for the study of general bacteriology. Without pure cultures this study becomes an effort in futility! Aseptic technique will be demonstrated by the lab instructor and the student should become quite familiar with the procedure to aseptically transfer bacteria from pure cultures. In general, pure cultures of isolated bacterial colonies are best obtained by using solid media and streak plates are primarily used for this purpose. >>>>> Each student will receive a tryptic soy agar plate and a tube of broth containing a mixture of bacteria. The "four-way" method will be used to streak the plate. This will be demonstrated by the instructor and is described below. 1. Never remove the top of the plate but lift the lid just high enough to make complete strokes. 2. Place a loop of organisms on one edge of the agar (area 1) and then streak back and forth, overlapping the streaks until you have covered about one fourth of the plate. 3. Flame the loop before proceeding to each of the other steps 4. Turn the plate approximately 90° and start streaking from one corner of the streaked area 1 and cover about one fourth of the surface (area 2). Turn again and streak surface area 3 by overlapping area 2, as shown below. Repeat this method and streak the surface of area 4 but do not run the final streaks back into any of the previous areas. You have now spread the Exercise 1 file:///C|/WINDOWS/Desktop/clown/Microb Lab Web 2001/Exercise1/exercise1b.htm (1 of 6) [8/31/2002 4:29:54 PM]