lab practicum

Question 1

aseptic technique

Answer 1

procedures set to minimize contamination of laboratory workers, their samples, and their surrounding

Question 2

colony of bacteria

Answer 2

visible mass of bacterial growth of a single bacterium

Question 3

The mouth of a culture tube must be flamed after the closure is removed and before it is replaced, why?

Answer 3

to prevent contamination from “outside” air. Hot air rises, eliminating other airborne bacteria. This DOES NOT sterilize.

Question 4

pure culture

Answer 4

a collection of a single species

Question 5

Why should your loop never be placed flat on bench top?

Answer 5

As to not contaminate, and to prevent confusion whether it is or is not contaminated

Question 6

Why are Petri dishes stored and incubated upside-down?

Answer 6

to prevent condensation falling into dish and precent exposure, accidental contamination to culture

Question 7

Hand must be held higher than the portion of the loop being flamed, why?

Answer 7

So flammable liquids don’t drip down to your hand!!

Question 8

Flame loops between each streak, why?

Answer 8

to rid of remaining bacteria and effectively dilute concentration of bacteria

Question 9

Bacterial smear is

Answer 9

A small amount of bacteria spread across a glass microscope slide

Question 10

Simple stain

Answer 10

Bacterial smear is treated with a single dye to view in a microscope.

Question 11

differential stain

Answer 11

It is one that uses more than one dye to stain bacteria, which allows two or more bacteria to be identified

Question 12

types of differential stains

Answer 12

GRAM strain and spore stain