Microbiology Lab Final Chat Study Guide

total magnification formula

total magnification = ocular x objective

coccus

spherical

bacillus

rod

spirillum

spiral

diplo-

pairs

strepto-

chains

staphylo-

clusters

true motility

directional movement

Brownian motion

random vibrating

streaming

all organisms move in same direction with fluid

Oil immersion

Used only with 100x objective

Simple stain

Uses one dye. Everything stains the same color.

Negative stain

Background stains, cells stay clear.

Gram positive

purple, thick peptidoglycan, teichoic acid

Gram negative

pink/red, thin peptidoglycan, LPS outer membrane

Staphylococcus epidermidis

Gram positive cocci

Escherichia coli

Gram negative rod

Bacillus subtilis

Gram positive rod

colony

visible mound of millions of bacteria from one cell

broth

liquid

agar plate

solid

deep

semi-solid

Streak plate

Purpose = isolate single colonies

TTC motility test positive

growth spreads out from stab line

TTC motility test negative

growth only on stab line

obligate aerobe

growth at top only

obligate anaerobe

growth at bottom only

facultative anaerobe

growth throughout, heavier at top

aerotolerant

even growth throughout

microaerophile

thin band below top

Sugar fermentation positive

yellow

Gas production

bubble in Durham tube

SIM test H2S production

black precipitate

Indole positive

red layer on top

Indole negative

yellow layer

Catalase positive

bubbles

Catalase negative

no bubbles

Starch hydrolysis positive

clear zone around growth

Starch hydrolysis negative

dark blue/black everywhere

Urease positive

hot pink

Urease negative

peach

Citrate positive

ANY blue

Citrate negative

green

Zone of inhibition

clear area around disk

bactericidal

kills

bacteriostatic

inhibits growth

epidemic

excess cases in one area

pandemic

multiple continents

epidemiology

study of disease spread

transmission

direct vs indirect contact

Acid-fast positive

red

non-acid-fast

blue

endospore

green

vegetative cell

red/pink

Capsule stain

clear halo around cell = capsule