BACTERIAL STAINING LAB

Question 1

how is a stain (dye) chemically defined

Answer 1

organic compound:

a benzene ring (organic colorless solvent )
+
a chromophore (chemical group that adds color to benzene)

_________________
^ these two refered to as a chromogen

+
and auxochrome group (property of ionization to the chromogen, enabling it to form salts and bind to fibers or tissues)

^ enables the binding

Question 2

t/f all bacteria cells are anionic

Answer 2

true

Question 3

ability of a stain to bind to macromolecular cellular components such as proteins or nucleic acids depends on electrical charge found on the _____ as well as on the ______

Answer 3

chromogen portion, as well as on the cell component being stained

Question 4

are proteins cationic or anionic

Answer 4

cationic +

Question 5

t/f proteins will readily bind to and accept the color of negatively charged anionic chromogen of an acidic stain

Answer 5

true

Question 6

picric acid is an example of a ______ chromogen

Answer 6

anionic, acidic stain

Question 7

basic stains are cationic because of + charge on _____

Answer 7

chromogen

Question 8

are nucleic acids negatively charged or positive chared cellular components

Answer 8

negatively (anionic),

Question 9

what type of acid do nuclic acids bind readily to

Answer 9

basic stains, the cationic chromogen of a basic stian

Question 10

____ on the bacterial surface acts to repel most ____ stains

Answer 10

negative charge acidic

Question 11

two types of staining techniues

Answer 11

simple staining
visualize morphological shape (cocci, bacilli, spirlli) as well as