General Lab Info Lab Midterm – 100 pts Lab Final – 100 pts Lab Assignments – 32 pts This may include This may include weekly in-lab assignmentsweekly in-lab assignments quizzesquizzes Lab Participation – 18 pts 1 pt each week for signing in on time 1 pt each week for signing in on time 1 pt each week for proper cleanup 1 pt each week for proper cleanup
Lab Protocols Be on time Read your lab prior to lab Clean up after yourselves
Biohazard Disposal Put tubes in tube rack Put plates, pipet tips, microtubes, etc in biohazard bucket Put dirty slides in “Dirty Slides” bucket Put broken glass in “Broken Glass” bucket
Lab Safety No food or drinks Clean your lab bench with disinfectant before and after lab Report any broken glass or injuries immediately Be aware when using bunsen burners
Exercise 1 - Scavenger Hunt Objective: Find items commonly used in lab
Exercise 2 – The Unseen Organism Bacteria and some Fungi are too small to be seen, but are everywhere (ubiquitous) Objective: Demonstrate that microorganisms exist in the air and on surfaces
Types of Cultures/Media Broth – liquid Slant – solid, agar containing tube, dried at an angle Plate – solid, agar containing petri dish We will use many types of media throughout the quarter, each having different nutrients/properties
Aseptic Transfers Movement of bacteria from one media culture to another, without introducing contamination Tools Loop Loop Needle Needle Flame Flame Sharpie (label everything!!!) Sharpie (label everything!!!)
Aseptic Transfer, cont. Label the new, sterile media (initials and bacteria being transferred) Label tube glass or bottom of plates Label tube glass or bottom of plates Hold both tubes in hand not holding inoculating loop/needle Flame inoculating loop/needle until red hot Cool ~15 seconds Remove both caps with little finger Pass tube opening through flame Take inoculum from tube and quickly place in/on new medium Flame tube openings Recap
Exercise 3 - Culture Transfer Techniques Objective: Transfer a bacterium from a culture to sterile media without introducing contamination Each group of 4 students will need: 2 broth tube 2 broth tube 2 slant tube 2 slant tube 2 agar plate 2 agar plate Transfer Micrococcus luteus broth to each type of media Transfer Micrococcus luteus slant to each type of media Place tubes in incubation rack and plates in tub (always incubate plates upside down!!!!)
Microscope Care Make sure lenses are clean (w/lens paper) Store with lowest power objective lens in position Stage should be all the way down Turn power off
Tips for Using the Microscope Always start on the lowest power (4x) Use course focus to bring object into view Use fine focus to make the image sharp Move to the next power Use only the fine focus from here on out Before you get to the 100x lens, put a drop of oil on the slide Use the iris diaphram and light intensity to adjust light levels
Exercise 4 – ID of Cells Objectives: Recognize visual differences between prokaryotic and eukaryotic cells; Identify three basic morphologies of prokaryotic cells. Eukaryotic – cells of animals, plants, fungi, and protists. Contain membrane bound organelles Prokaryotic – cells of bacteria. No membrane bound organelles. 3 basic shapes Cocci = sphere Cocci = sphere Bacilli = rod Bacilli = rod Spirilla = spiral Spirilla = spiral
Staphylococcus aureus Gram-positive, cluster forming (like grapes) cocci Normally found in nose and on skin Can cause pneumonia, nosocomial infections, food poisoning, TSS
Bacillus cereus Gram-positive rod Causes gastrointestinal intoxication Found in a wide variety of foods
Yeast Eukaryotic Fungus Used in making beer, wine, and cheese Can form symbiotic relationship with bacteria Note: These cells are round, but we do not use the term “cocci” for eukaryotic cells.
Human Blood Smear Eukaryotic cell Note: These cells are round, but we do not use the term “cocci” for eukaryotic cells.
Note the size difference between prokaryotic and eukaryotic cells
Exercise 5 - Motility Objective: Determine if a bacterium is motile Some bacteria have the ability to move toward or away from a stimulus TTC will turn red along the path traveled by the bacterium
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