Microlab practicle

What is resolution

minimun distance between two objects that can be seen clearly.

what is paracentric

when a mircoscope stays in center as you move the objectives - what we use

what is this arrangment

spirrilum

filamentous in mycellium arrangmeent

what is parfocal

microscope stays in focus when switching lenses

what is this arrangment and shape

strepto and coccus

what is a bacterial smear

a micriscope slide with bacteria mounted by smearing a cover slip over droplet

what is the most important step when staining bacteria to a slide

you need to heat fix it so the bacteria dont slide off during staining

what is a basic simple stain

uses ionionized chrmomaphores

what is a gram positive stain

using positive phromophores like methylene blue

what is a gram postive stain

negatively charged chromophores to stain cell red

what is the most important step in a streak plate

innoculate loop needs to be sterilized between each streak

what is the main difference between gram negative and gram postive bacteria

gram positive have peptidoglycan layer and gram negative has LPS. Binds to stains differently

how many microliters in this pipette when loaded

750ul

what is diffusability

can color diffuse through media

what is raised, convex, umbonate, craterform

type of colony elevation

raised - small bump

convex- pronounced dome

umbonate - extra bubble on top

craterform - depression in colony

what are two ways ot describe colony texture

shiny , mucoid,dry, or wrinkled

what are two ways of describing edge and margin

entire or wavy

what are ways of describing turbibity (cloudyness)

transluscent - seethrough

sediment - clump on bottom

pellicle - growth at top

how do you stain an endospore

use malachite green and heat it into the endospore capsule and rinse it out, then counter stain with safranin

what is a motility medium

a medium with less agarose so its more jelly and requires a straight stab

what is a hanging drop test

it is placing free bacteria in water and observing them for motion

what is brownian motion

bacteria seem like they are moving but are vibrating as the water around them heats up

what is a psychrophile

bacteria that likes cold temp

what is a mesophile

a bacteria that likes mild temperature 25-37* celcius

what is a thermophile

bacteria that like warm temps below 45*

what is an hyperthermophile

bacteria that live in very hot temps

how do you measure UV sensitivity of bacteria

exposure and then grown on medium with control to see if growth occured

what is an obligate anaerobe/aerobe

has to have either lots of oxygen or absolutely none

aerotolerant anaerobes

dont use oxygen but can tolerate it

faculative anaerobe

can use both oxygen or no oxygen

microaerophile

very small concerntration of oxygen can be present

what does methyl red and vogus prox measure

it measures pathway bacteria use for glucose

what does methyl red react to

ph change below 6 which dhows mixed acid fermentation of glucose immediate color change

what does vogus prox measure

prescence of butadiol in fermentation of glucose will present as red band at top of culture after 30 mins

what does the oxidative fermentation measure

weather bacteria use carbon sources in prescence of absensce of oxygen

what things are included in the media of vp test

bromythl blue which changes to yellow when saccaride is used or if turns all the way blue it is a raise in ph

what molecules are used in quorum sensing

AHLS

what is a positive result of quorum sensing

purple hue between bacteria and C violaceum

what does a positive maconey lactose look like

it has a pink hue and shows that the bacteria

what are three characteristics of a maconey lactose

selective, complex, differential

what is a complex vs defined media

a complex media has complex protiens and mixture while defined only has one thing present

what is a selective media

only some bacteria can grow on the media

what is a differential media

a media that shows you a color change or clear posittive vs negative result

what is a characteristic of urease using bateria

they thrive in a low ph enviroment like the stomach

what color does urease change and what is unique about it

it changes pink in response to a high ph

what is selective toxicity

selective toxicity is when antimicrobes present deadly to bacteria but not humans

what is bacteriostatic and what would it show on OD500

prevents further growth so should show no change from control

what is bacteriolytic

agents that lyse the cell completely and will result in a decrease of OD500

what is bacteriocidal

kills bacteria so loss in viable cells but no change in OD500

what does catylase do

it detoxifys free radicals of oxygen preventing them from killing the cell

what are you looking for in a postive catalase test

the prescence or absence of bubbles

what is the purpose of the oxidase test

is is differential to gram negative bacteria and will determine if oxidase is present and will turn blue on the paper

what are the characteristics of a citrate medium

semi-selective differential and defined

What does the citrate test look for

it will turn blue under alkaline conditions and shows that the bacteria uses citrate to convert citrate to pyruvate

what are two ways to get a postitive citrate test

either observing a color change or general growth on media

what is the purpose of gelitanase test

can show wether bacteria grow and digest the galatin resulting in shaky media

what are the parts needed for pcr

bases, dn poly, primers, template dna and reaction buffer

what are the three paerts to pcr

1. Initial denaturation

2. Aplification

   1. denaturing

   2. annealing

   3. extension

3. FINAL EXTENSION

how does gel eletrophoresis work

it works by putting dna fragments through an ionized chanber with a postitive and negative side. Larger fragments will move slower

what does a biofilm assay show

an elevated level of OD500 due to increased biofilm production

what does the nitrate test do

determines wether bacteria can reduce nitrate to its gas or other form

what are postitive results of a nitrate test

Presence of bubble in Durham tube suggests reduction of nitrate into nitrogencontaining gasses.

• Presence of red color after addition of reagents A and B is indicative of Nitrate reduction to Nitrite

• Presence of no color change after addition of Zinc dust is indicative of Nitrate and subsequent Nitrite reduction

what is a negative result of a nitrate test

pink color change after the addition of zinc

why are capsules good for bacteria

it allows them to prevent immune cell binding, adhere to surface or prevent water loss

in gram postitive stains what is stained

the bacteria

what is stained in negative stains

the background