Laboratory Safety, Microbiology Concepts, and Microscopy Essentials

Flashcards covering lab safety, biosafety levels, hand hygiene, environmental sampling, culture media, and microscopy concepts from the provided lecture notes.

What biosafety levels are used in CSN Microbiology labs?

BSL-1 and BSL-2.

What does BSL stand for and what is its purpose?

Biosafety Level; a framework of practices and barriers to safely handle infectious organisms and protect personnel and the environment.

BSL-1 organisms are associated with what health risk?

Not known to cause disease in healthy humans.

What are the typical protections for BSL-1?

Standard practices, open bench work, no special containment; autoclave available.

BSL-2 features include?

Associated with human disease but easily contained; limited access; PPE; BSC for procedures.

BSL-3 requires what containment and equipment?

Class II biosafety cabinet and containment devices; complete isolation; restricted access.

Which examples correspond to BSL-3 and BSL-4 in the notes?

BSL-3: Mycobacterium tuberculosis; BSL-4: Ebola virus.

Where should personal belongings be stored in the CSN lab?

Lockers.

Who may work in labs without instructor supervision?

No one; lab work requires supervision.

What PPE must students wear?

Protective clothing/equipment designated by the instructor (lab coats, goggles, gloves, etc.).

What must be done with lab materials and the work area at the end of a session?

Clean up, put away, leave the area clean and dry.

Where should waste be disposed of?

In the manner designated by the instructor.

What should you do if there is a fire in the lab?

Inform the instructor, evacuate, pull the fire alarm, inform CSN security.

How should classroom accidents or injuries be reported?

Reported to the instructor immediately.

Where can you find emergency procedures?

In the Hazardous Materials Right to Know Safety Training manual (Section XIII), location provided by instructor.

What is required for lab coats in this course?

Lab coats are mandatory and autoclaved; stored in a bag labeled with your name; returned last week.

How should goggles be stored and worn?

Goggles required; stored in a sealed bag with your name; cover eyes and have side shielding; cleaned with disinfectant at end.

What is the glove protocol in the lab?

Disposable gloves provided; wear while staining/working with cultures; remove by turning inside out via cuff; dispose.

When is a Biosafety Cabinet used in this lab?

When working with BSL-2 and liquid cultures to contain aerosols.

What are the basic hair and shoe guidelines?

Closed-toe shoes; tie back long hair.

What is the correct handwashing sequence?

Wet hands, apply soap, scrub 15-20 seconds (palm to palm, interlace fingers, rub tops/nails), rinse, dry, use towel to turn off water.

Why is bench disinfection performed before and after lab work?

To prevent cross-contamination and remove residual microbes.

What is meant by the ubiquity of microbes?

Microorganisms are everywhere in every habitat on Earth.

What is normal microflora and its role?

Resident microbes on skin/hair follicles that help health by producing beneficial products and inhibiting pathogens.

Name examples of resident flora on human skin.

Staphylococcus epidermidis; Corynebacterium; Propionibacterium.

What is transient flora?

Temporary microbes acquired from touching contaminated surfaces; can cause nosocomial infections; easily removed with proper handwashing.

Name some nosocomial pathogens mentioned.

MRSA, VRE, Clostridium difficile; also E. coli and Salmonella in food poisoning.

What are the four types of culture media and their purposes?

General purpose (growth of many microbes, e.g., TSA); enrichment (special growth factors, e.g., BAP); selective (inhibit some groups to favor others, e.g., SDA for fungi); differential (show differences between colonies, e.g., BAP hemolysis).

What does TSA stand for and what is it used for?

Tryptic Soy Agar; general purpose medium for growing many microorganisms.

What does SDA stand for and what is it used for?

Sabouraud’s Dextrose Agar; selective medium that inhibits bacteria and promotes fungi.

What does Blood Agar Plate (BAP) do?

Enrichment and differential medium containing blood to show hemolysis patterns.

At what temperatures are plates incubated for molds and bacteria, respectively?

Molds at 25°C; many bacteria at 37°C.

What is a colony in microbiology?

Visible mass of microbes on agar, typically derived from a single cell; colonies vary in shape, color, and size.

What is the typical goal of inoculating environmental samples on TSA and SDA?

To compare growth of microbes from the environment on general and selective/differential media.

What is a wet mount?

A method to observe living specimens under a microscope using a liquid mount.

What are the common ocular and objective lens magnifications used in this lab?

Ocular 15x; objectives 4x, 10x, 40x, 100x.

What does parfocal mean?

An image that stays in focus when switching from one objective to another; only fine adjustment is needed.

Why is oil used with the 100x objective?

To match refractive indices and reduce light bending, increasing resolution.

What is the formula for total magnification?

Total magnification = ocular magnification × objective magnification.

What is the function of the condenser in a light microscope?

Concentrates light onto the specimen and is controlled by the iris diaphragm.

What are prokaryotic cells and which domains include them?

Small, lack a true nucleus and membrane-bound organelles; domains Bacteria and Archaea.

What are eukaryotic cells and which domains include them?

Larger cells with a nucleus and membrane-bound organelles; domain Eukarya.

What kingdoms are in Eukarya relevant to microbiology?

Protista, Fungi, Plantae, and Animalia.

What is Volvox?

A polyphyletic genus of multicellular freshwater green algae.

What is a fomite?

An object that can carry microbes from one person or place to another.

What is the purpose of the Glo-Germ handwashing exercise?

To illustrate the effectiveness of handwashing by showing fluorescence under UV light where microbes remain.

What is the recommended storage practice for lab slides and prepared materials after use?

Do not discard prepared slides; follow instructor guidance for storage and disposal.

What is the recommended handling for lab waste in this course?

Dispose of waste materials in the manner designated by the instructor.

What should you do after finishing using a microscope?

Turn off the light, return to lowest objective, wipe oil, lower stage, wrap cord, and place in proper location after instructor checks.

What does it mean when it says “Microbes can live in symbiotic”?

relationships with other organisms, benefiting both species.

What is the definition of commensals?

Organisms that live on or in another organism without harming it, often benefiting from it.