Lab #3

What is a smear?

a layer of cells fixed on the surface of slide glass w/out changing the morphology

What is staining?

Coloring bacteria to improve contrast and allowing cells to be more visible

What are the 2 types of basic dyes?

Direct stains
Acid stains

Acid dye remains ___ the cell. Basic dye remains ___ cell giving color

outside
inside

what is simple stains?

uses only 1 dye

What are the 2 different types of simple stains?

direct stains (stains bacteria)
negative stains (stains background)

What is differential stains?

uses more then one dye

what are the 2 different types of differential stains?

gram stain( gram+/ -)
acid fast stains (acid/nonacid)

What is special (structural) stains

use to identify external/internal

what are the 3 forms you can use to identify using special (structural stain)

endospore
capsule
Flagella

describe gram postive

retains primary dye
purple (circle)

Describe gram negative?

dont retain the primary dye
pink (rod)

What are the dye you need to perform a gram staining

crystal violet
gram Iodine
95% Ethanol
safranin

What color are each ?
gram +
gram -

purple
pink

Differential stain lead to the discovery of ____

mycobacterium tuberculosis

In a Acid fast stain cell wall have high percentages of ____ which retains dye when decolorized with acid alcohol

Mycolic acid

What is endospores?

resting structure used to protect when in harsh enviroment

what are the positions of an endospore?

central
subterminal
terminal

What is capsule? and what is it important of ?

a sugar coat of bacteria,
important for virulence

Can capsule be stained?

No

How can you view a capsule stain?

negative stain (nigrosin/congo red)

What is flagella ?

helps with motility