Med Micro Lab - Info for 1st Quiz

what does the door into the lab look like?

decorated with signs and warnings; it is explained how it is a Bio Safety Level 2 facility

what are the signs like on the laboratory door?

there are notice signs about clothing, dress, food, drink (are you prepared?); there is an emergency phone number, a lab schedule, and a biohazard warning sign

where is the safety call button?

to the left of the door if you are exiting the lab; located to the right of the fire extinguisher, and it is a silver color; it is also to the left of the fire alarm

what is the most important thing you need to do in this lab?

wash your hands

what do you need to do to the bench before and after lab?

clean with bleach and paper towels; do not wipe completely drive to allow it to continue to kill the microbes on the bench

what is the sign that looks like its been destroyed?

explosive

what is the sign with the flame?

flammable

what is the sign with the circle and the flame?

oxidizing

what is the sign with the tube that has a short, extended end?

compressed gas

what is the sign with the exclamation mark?

harmful/irritant

what is the sign that appears to have a tree on it?

dangerous for the environment

what is the sign that has a human on it?

health hazard

what is the sign that has pouring liquid on it?

corrosive

why is immersion oil dangerous?

it is a potential carcinogen, so wash your hands carefully after using

where is the fire extinguisher?

to the left of the door inside of the lab, to the left of the light switch

where is the security call button?

to the left of the door on the outside to the right of the fire extinguisher

where is the eye wash station?

it is a green container to the left side of the room to the right of the sink

where is the first aid kit?

straight back to the prep room when entering the prep room door

where is the flashlight?

sitting on top of the first aid kit in the prep room

what is step 1 of the spills procedure?

alert everyone in the vicinity of the spill, so they can avoid it

what is step 2 of the spills procedure?

report the spill to your instructor

what is step 3 of the spills procedure?

place paper towels over the spill and saturate the area with bleach

what is step 4 of the spills procedure?

put on gloves

what is step 5 of the spills procedure?

wipe the spill up with more paper towels

what is step 6 of the spills procedure?

place paper towels in the biohazard container on your bench

what is step 7 of the spills procedure?

wash hands, disinfect clothing if necessary

what are inoculating instruments (loops and needles) used for?

to transfer organisms and small amounts of fluid

what is the flint liter used for?

to light Bunsen burners

what is a test tube rack used for?

to hold and organize materials and test tubes (always use when transporting)

what is ethanol used as?

a destainer and disinfectant (extremely flammable, so keep away from Bunsen burner)

where can you find microbes?

on every surface, isolated from water, plants, animals, soil, and air samples

what are organisms that are avirulent?

those that are not pathogenic and do not cause disease

what are the microorganisms on the human body that are beneficial?

normal flora or natural microbiota

what does the Infectious Dose do?

varies according to the type of microbe encountered and their ability to establish infection

what is used to prevent contamination of our experiments with microorganisms from the environment?

aseptic technique

what is it called when you sample the environment around you and grow it?

growing a culture of bacteria

what do TBAB petri plates contain?

a growth medium/media (nutrients and water) with agar

what is agar?

a solidifying agent that allows for the growth of most organisms that can tolerate an aerobic environment

what is nutrient broth?

liquid media without agar (contain the same nutrients as the TBAB plates)

when using a swab to inoculate a plate, why do we usually attempt to separate the organisms present?

to lead to isolating a pure strain of organisms

what was the broth culture used in our very first lab?

staphylococcus

why do we place the TBAB plates upside down during incubation?

so condensation does not occur and mess with the growing bacteria

what personal item was sampled in lab 1?

the bottom of my shoe

is it expected to see more than one strain of bacteria after swabbing the bottom of a shoe?

yes, because there are several different types of bacteria on the ground where we walk

why is incubation at 37 degrees celsius?

because that is the danger zone temperature that is the same as body temp, which allows for the quickest growth

what is 37 degrees C in F?

98.6

what does aseptic technique help with?

it helps to prevent microbial contamination and transmission of disease

what is turbidity?

cloudiness of the broth (usually the best indication that growth has taken place)

what is a biofilm?

a film that can form on almost any surface and may be seen floating on the top of the nutrient broth

what is the biofilm called that is formed on the top of the liquid broth?

a pellicle

what is a mass of settled organisms at the bottom of the tube called (it can also be resuspended into the broth)

a sediment

what can you do to better see turbidity?

gently tap/shake the tube

what is binary fission?

when a single bacterial cell is placed onto a solid surface containing nutrients and then incubated, the bacterial cells divide

what is it when there are enough bacterial cells to make a visible mass?

it is a colony

what are all the cells in a colony?

the descendants of that single bacterial cell initially deposited on the surface of the agar; are genetically identical

what is colony morphology?

the description that includes the bacterial colony configuration, margin, and elevation

what are some important characteristics that can help you identify bacterial strains?

color, smell, shape, margin, elevation

what are isolated colonies?

colonies that do not touch each other

what is it if some colonies grow alongside other colonies or maybe even on top of other colonies?

overlapping/merginc colonies indicate a mixed culture

what is a mixed culture?

one that has more than one species of organism present

what is a pure culture?

a culture that demonstrates the presence of only one bacterial species where all bacterial cells comprising the culture are genetically identical

what do you do if you want to grow a lot of bacteria from one colony?

aseptically transfer the selected colony to a broth (liquid media)

why would one transfer a colony to a slant?

for short term storage of that organism

what is aseptic transfer?

the selection of colonies from one culture for inoculation and growth in a different culture without contamination with unwanted organisms

what is the goal of the 4-way streak method?

to obtain isolated colonies

a 4-way/3-way streak method is the only way to determine what?

the morphologies of the colonies and help determine where the culture is pure or mixed

what are slants typically done with?

pure cultures

what is the purpose of using a plate?

to obtain isolated colonies

what is the purpose of a slant?

short term stock storage

what is the purpose of a broth?

to obtain high numbers of bacterial growth (metabolic)

what is the growth of a bacterial culture?

an increase in cell number, not size

what is logarithmic growth?

the speed of doubling

what is serial dilution?

when one dilutes the sample by a facter of 10 several/multiple times to make it easier to view the colony

what does serial dilution lead to?

a resulting colony count of CFU/ml (colony forming units per milliliter)

what is TNTC?

too numerous to count

what is TFTC?

too few to count

what is the first phase of bacterial growth?

lag phase

what is the second phase of bacterial growth?

exponential growth phase

what is the third phase of bacterial growth?

stationary phase

what is the last phase of bacterial growth

death phase

what is subculturing?

when an organism on solid media reduces the cell density, and eventually leads to individual cells being deposited on the surface of the media

having isolated colonies does not mean what?

that the culture is pure

what is the purpose of using liquid media to grow organisms?

to grow large quantities of microorganisms in suspension with a uniform distribution of nutrients and oxygen

what characteristic must bacteria have to cover areas of the agar that you did not inoculate?

it must have motlity (flagella)

would you expect to see isolated colonies from an inoculated slant?

no (because the growth merges into a mass)

what is the process of heat fixing?

using heat to cause bacteria to adhere to a slide so it can be stained/observed, but also killing them to render pathogenic bacteria safe to handle

why do we use 0.85% NaCl with a smear? (think about tonicity)

because it is isotonic to human cells and bacteria

how to mess up a smear?

1. use too much material

2. use so much liquid it takes forever to dry

3. head the smear before letting it air dry (boiling bacteria)

4. overheating the smear, melting the cell walls, and possibly breaking the slide

what can a simple basic stain be used for?

to distinguish cell morphology and arrangement of bacteria

what can a simple stain not do?

differentiate between gram-positives and negatives

what is used for simple staining?

Crystal Violet (purple)

what is a dichotomous key?

a way of identifying organisms based on characteristics that can be determined by observation or experimentation, and often have questions that can typically be answered by two different answers (di)

what is the first step/question when identifying bacteria?

what is the gram reaction?

after a bacterial cell divides, the daughter cells assume a characteristic what?

morphology, that varies widely between species

what are the two major shapes found among bacteria?

cocci and bacilli

what is cellular arrangement?

how multiple bacteria group together and appear as seen by microscopic examination after staining

what is bacteria that divide in one plane?

diplococcus or streptococcus

what are bacteria that divide on two planes, producing a tetrad arrangement?

staphylococcus

what are diplococci?

paired cocci that consist of the mother and daughter cell

what are streptococci?

cocci that form chains of cells after division