Lap Practical – Flashcards
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Unlock answers| what is undefined media or complex media? |
| growth media whose exact composition and amounts of carbon and nitrogen in the ingredients are unknown |
| What are examples of complex media? |
peptones: beef and cheese phytones: plant extracts and yeasts |
| what is a resovoir? |
| site outside organism or where microbe resides and is possible for infection |
| what are some basic categories of colony morphology? |
shape, margin, elevation, texture, pigment
|
| what types of shapes are there |
| round, irregular, punctiform |
| What are the margins? |
| entire (smooth), undulate (wavy), lobate, filamentous, rhizoid |
| What are some types of elevations? |
| convex, flat, raised, pulvariate, umbonate |
| why do you use agar slants? |
-cultivation and maintenence -displays a variety of growth characteristics |
| why are agar slants better than plates? |
-grow high cell densities -less contamination -storage capacity -don't dry as fast |
| why are agar plates better than slants? |
-better use for isolation -produces single colonies |
-smooth texture with solid edge ; |
| FILIFORM |
| produces colored growth |
; PIGMENTED |
solid growth seeming to radiate outward ; |
| SPREADING EDGE |
rough texture with a crusty appearance ; |
| FRIABLE |
suspended chunks of pieces ; |
| FLOCCULENT |
growth on the bottom ; |
| SEDIMENT |
growth at top around the edge ; |
| RING |
membrane at the top ; |
| PELLICLE |
| Uniform Fine Turbidity |
| evenly distributed throughout |
| Benefits of broth cultures |
-grow high cell densities -oxygen requirements can be observed |
| What is fastidious |
| difficult to grow and needs special conditions |
| What are undefined (complex) media composed of? |
-extracts from plant/animal sources -rich in nutrients |
| The medium fluid thioglycollate can cultivate which microbes? |
aerobic, anaerobic, fastidious, nonfastidious---used for oxygen tolerance
-anaerobic and microaerophilic bacteria |
| what are the effects of resazurin? |
-pink when oxidized -colorless when reduced |
| which type would you find growing throughout the tube? |
faculative anaerobe aerotolerant anaerobes |
| Why is it important to use fresh FTG? |
| because agar used to slow O2 diffusion, so more time will cause greater O2 diffusion which is not beneficial for anaerobes |
| what does the Gas Pak anaerobic jar do? |
| created anaerobic, microaerophilic, or CO2- enriched conditions |
| What is the Anaerobic Gas Jar Indicator? |
| methylene blue strip that turns BLUE when oxidized and colorless when reduced |
| what color will the methylene idicator strip turn in anaerobic conditions? |
| white (reduced) |
| what is the function of the condenser lens? |
| concentrates light and makes illumination of specimen more uniform |
| What is refraction? |
| the bending of light as it passes through the objective lens |
| What is the 'limit of resolution'? |
| the measurment of how far apart two points must be to be viewed as being seperate |
| What is numerical aperature? |
| len's ability to capture light coming from specimen and use it to make an image |
| what does oil immersion do? |
| increases NA which makes limit of resolution smaller |
| What are heterocysts |
| Nitrogen fixing cells |
| What are akinetes? |
| resistant spores |
| what is an auxochrome |
| the charged portion of a chromogen (colored molecule) |
| what is a basic stain? |
auxochrome becomes a + charged by picking up H+ or losing OH- and is able to stain bacteria |
| Preparation for negative stain |
1. begin w/ acidic drop on one side of slide 2. add organisms 3. draw back 2nd slide until width of slide and then push to opposite end 4. let air dry |
| how do you know which are acid fast or nonacid fast |
acid fast- reddish purple nonacid fast- blue |
| Capsule stain procedure |
1. drop of congo red on one side 2. add organisms 3.draw back 2nd slide until width of slide and then slide to opposite side 4. air dry 5. flood with Manevals stain 6. rinse and dry |
| Schaeffer-Fulton Procedure |
1. heat fixed emulsion 2. cover smeal w/bibulous paper 3. flood with malachite green 4. steam for 5-10 min 5. rinse 6. counterstain with safranin 1 min 7. rinse and dry |
| what do wet mount and hanging drop preps allow you to do? |
| determine motility, natural cell size, arrangement, and shape |
| benefits of the hanging drop preparation |
| allows for long-term observation of a living specimen |
| Hanging Drop Procedure |
1. add petroleum around mouth of depression slide 2. drop water on cover glass 3. add bact 4. place depression slide over cover glass |
| How do you know if there is motility? |
| Motility: red (reduced) TTC is seen radiating outward from central stab line |
| What is TTC? |
Tetrazolium salt -used by bacteria as an e- acceptor -when oxidized its is colorless and soluble -reduced: red and insoluble |
| opportunistic infection |
| infection caused by pathogens that do not cause disease in healthy person |
| in the nitrogen cycle column what are the regions from top to bottom |
aerobic microaerophilic anaerobic hydrogen sulfide |
| what is the theory for isolation |
| to identify unknown microbes by obtaining a pur culture |
| what is the purpose of endospore stain |
| to detect the presence and location of spores within a cell |
| what are acid fast stains used for? |
to identify acid fast bacilli used to identify bacteria in the genus Mycobacterium only done when an infection is thought to be about |
| purpose of negative stain |
| identify morphology and cell arrangement in bacteria that can't withstand heat fixing |
| what is a slightly curved rod |
| vibrios |
| what is it called if division of cells happen in two planes? three planes? |
-tetrad -sarcina |
| when is arrangement and morphology easiest to see |
| when orgs ar grown in a broth or observed from a direct smear |
| The demand for nutrients and production is proportional to ______. And the ability to transport nutrients in and out of cell is proportional to ______. |
cell volume surface area |
| does SA or volume increase more rapidly? |
| volume |
