SCUHS Microbiology Lab - Exam 1 Study Guide Questions And Correct Detailed Answers Pass Guaranteed.

What are the different types of PPE found in the lab? - correct answers gloves and goggles BSL2 - biosafety cabinets BSL3 - respirators, and double gloves BSL4 - hazmat or pos pressure suits What are the different biosafety levels? Which one is the most dangerous? - correct answersBSL1 - least risk/harm, do not typically cause disease BSL2 - may cause disease BSL3 - causes potentially lethal disease BSL4 - causes deadly disease without treatment or vaccine What are some hazards that you can find in the lab? (refer to virtual lab) - correct answerssharp objects: scalpels, needles, knives chemicals: acids, bases, alcohols, preservatives Fire and other hot objects lab organisms: bacterial, tissue culture cells, dead rats and mice What are some items not allowed in the lab? - correct answersfood and drink open-toed shows and sandals loose clothing and accessories cell phones and personal electronics personal items in pockets chemicals and reagents from outside the lab smoking and open flames What are the steps to wash your hands? - correct answerswet hands, apply soap, lather under running water for at least 20 seconds, rinse hands, dry with paper towels, use paper towel to turn off faucet What is media? What is broth vs solid media? What ingredient makes media solid? - correct answersMedia: any substance used to grow microorganisms in the lab; contains nutrients liquid media = broth solid media = has agar added What is autoclave sterilization? What is ethylene oxide sterilization? - correct answersautoclave sterilization - high heat with pressure and steam. Good for media, liquids, plastics, etc, most commonly used in microbio ethylene oxide sterilization: gas that kills microbes. can be used for all types of materials including glass, plastics and other solids What does sterility mean? - correct answersremoving all life forms including spores and viruses What is a contamination? - correct answersgrowth of unwanted microbes How do you inoculate a broth? Slant? Deep? - correct answersinoculating a broth, slant or deep tube with a microbial culture involves transferring a small amount of culture into the target medium to initiate or propagate microbial growth. The method you use for inoculation can vary. inoculating a broth: sterilize an inoculating loop or pipette, and use to obtain a small amount of the microbial culture from the source, carefully open the broth tube, and insert the loop or pipette, avoid touching the rim. gently swirl the loop or pipette to mix the culture into the liquid. recap. inoculating a slant: streak the loop containing the microbial culture in a zigzag or streak pattern along the surface of the agar slant. replace cap and label. store in upright position to allow the slant surface to dry before incubation. inoculating a deep tube: insert the loop or pipette into the center of the medium and gently streak along the depth of the tube. avoid puncturing the bottom. replace the cap and incubate. How do you perform a four-quadrant streak? - correct answersa four-quadrant streak is a technique used to isolate individual bacterial colonies from a mixed microbial culture. use an inoculating loop to obtain a small amount of mixed microbial culture streak quadrant 1 in a zigzag pattern sterilize the loop, and then streak the loop containing culture across surface of q2 passing through the streaks made in q1. sterilize the loop, and then streak in q3 passing through the streaks made in q2 sterilize the loop and then streak in q4 passing through the streaks made in q2 method progressively dilutes the microbial culture across the surface of the agar, leading to the isolation of individual colonies in quadrant 4 that can then be further purified or studies. What is a bacterial colony and why is it important to get colonies when streaking for isolation? - correct answerscolony originates from 1 bacterial cell. all bacteria in a colony are theoretically identical to each other When would you use a loop versus a needle? - correct answersinoculating loops are used for: transfer and streaking on agar plates, culturing microorganisms in broth, and sample dilution (spread plate method) inoculating needles are used for: inoculating deep tubes, anaerobic cultures (can be purged of oxygen); puncture and stab cultures How do you label and store petri dishes? - correct answerslabel the bottom of the petri dish. avoid labeling the lid as condensation can cause labels to peel or ink to run. storage - stack petri dishes, upright with agar side up to prevent contamination of the agar surface. they can be stacked in columns and rows. store at the appropriate temp for the microorganism being cultured, protect from light of needed What is a pure vs mixed colony? - correct answersa pure colony aka pure culture or monoculture is composed of a single species or strain or microorganism. it arises from the growth and multiplication of a single microbial cell that was initially deposited on an agar plate. they are genetically uniform mixed colonies aka mixed culture, contain two or more different species or strains of microorganisms growing together on the same agar plate. multiple colonies with distinct characteristics grow side by side. What are the main parts of a microscope? - correct answerseyepiece - ocular lens objective lenses stage condenser - located beneath the stage and helps focus and concentrate light diaphragm - opening of condenser coarse and fine adjustment knobs base arm nosepiece stage clips or mechanical stage How do you properly use and store a microscope? - correct answersbefore use, inspect the microscope for dust or debris. clean with lens paper or lint-free cloth start with lowest magnification (4x objective), use the coarse knob to focus, and then fine tune with the fine adjustment change objectives, refocus using the fine adjustment knob for storage: - put back in low-power objective How do you focus a microscope until the 100X oil objective? - correct answersstart a low magnification switch to the 100x objective lower the 100 x objective close to the slide without touching it. apply a drop of immersion oil directly onto the slide, just above the area of interest on the specimen. carefully and gently swing the 100x objective into the immersion oil drop. use the fine focus knob What is a wet mount and what can you see in a wet mount? - correct answersa wet mount is a technique in which a small sample or specimen is suspended in a liquid and placed on a microscope slide for observation. the liquid helps maintain the specimen's hydration and allows for temporary examination of live or preserved specimens. they are useful for studying transparent or translucent specimens. you can see cellular structures, microorganisms, transparent specimens, motility, water quality, suspensions How do you calculate total magnification? - correct answersmultiply the magnification of the objective lens by the magnification of the eyepiece eg 40x objective x 10x eyepiece = 400x How do you prepare a heat fixed smear? - correct answerssmear is a sample of bacteria that are dried and heat fixed to a microscope slide use a loop to add a drop of culture to a slide (liquid media). let drop dry. pass slide over flame 2-3 times. if a solid culture: first add a drop of water to the slide and then add the bacteria to the drop What are the steps in gram staining? - correct answersCrystal violet - primary dye iodine - mordant alcohol - decolorizer safranin - counterstain What are the steps of acid fast staining? - corre