(Prelims) MicroBio Lab Exam 2 Flashcards
a substance that adheres to a cell, giving the cell color.
STAIN
to preserve the
shape of the cells or tissue involved as much as possible.
FIXATION
used to differentiate different types of organisms or to
view specific parts of organisms.
STAIN
means coloring the microorganisms with a dye
that emphasizes certain structures
STAINING
Microorganisms must be what? to the microscope slide before it can be stained.
Fixed
used to kill, adhere, and makes them permeable so it will accept stains.
heat fixation
a thin film of material containing
the microorganisms is spread over the surface of the slide.
SMEAR
The first step in most bacterial staining procedures
SMEAR PREPARATION
Three types of staining protocol or procedures:
- Simple Staining
- Differential Staining
- Specialized Staining
direct staining method that uses only one stain.
SIMPLE STAINING
Stains are salts composed of a positive and a negative ion, one of which is
colored and is known as the
chromophore.
Simple stains can be used to determine what
bacterial species’ morphology and arrangement, but they do not give any additional information.
is in the cation
basic dyes
What dyes are not attracted to most types of bacteria
Acidic dye
it is in the anion.
acidic dyes
Uses 2 or more stains and allow the cells to be categorized into various
groups or types.
DIFFERENTIAL STAINING
Gram staining procedure is developed in
1884 by whom
Hans Christian Gram
Used for identification or structure examination of bacteria in addition to
general morphological examination
DIFFERENTIAL STAINING
first stain
Primary Stain
Distinguishes 2 kinds of microorganisms
DIFFERENTIAL STAINING
second stain
Counter Stain
3 Types of Differential staining:
- Gram Staining
- Acid-fast staining
- Endospore staining
Gram Staining classification is based on the physical
properties of the what
Bacterial Cell Wall
A type of differential staining method that distinguishes bacteria into 2 groups
Gram Staining
referred as mordant because it increases the affinity of dyes or a stain for smear
Iodine/Gram’s Iodine
primary stain used in gram staining
Crystal Violet
referred as decolorizing agent that remove stain from
the specimen in gram staining
Alcohol
counterstain in gram staining
Safranin