STAINING Flashcards
1
Q
- Developed by Hans Christian Gram
- common technique used to differentiate two large groups of bacteria based on their different cell wall constituents.
- Facilitate visualization of the specimen by enhancing the contrast in the microscopic image with the use of a dye or stain
- Gives color; easier to see
A
Staining
2
Q
Basic dyes
A
Safranin
Methylene blue
Crystal violet
2
Q
- Make use of a single dye
- Water based or aqueous or alcohol based
- Quick and easy way to visualize cell shape, size and arrangement of bacteria
- Adheres to cell surface enabling visualization of bacteria cell
A
Simple Stains
3
Q
- colors cell nuclei red
A
Safranin
3
Q
Methods in Acid-fast Stain
A
- Zeihl-Neelsen stain
- Kinyoun Stain
3
Q
- turns the cell nuclei blue
A
Methylene blue
4
Q
- Used to differentiate one group of bacteria from the another
A
Differential Stains
4
Q
- Distinguishes gram positive bacteria from gram negative bacteria
- Gram positive bacteria: stain blue or purple
- Gram negative bacteria: stain red
- All cocci are gram positive bacteria except neisseria, veilonella and branhamella
- All bacilli are gram negative except corynebacterium, clostridium, bacillus and mycobacterium
A
Gram Stain
4
Q
Types of Differential Stain
A
- Gram Stain
- Acid-fast Stain
4
Q
- stains the cell nuclei purple
A
Crystal violet
5
Q
- stain used for bacteria with high lipid content in their cell wall (high mycolic acid) , hence cannot stain using Gram Stain
A
Acid-fast Stain
6
Q
o Hot method
o Requires steam bathing the prepared smear after addition of the primary dye
o Acid fast organisms will appear red on a blue background
A
Zeihl-Neelsen stain
7
Q
Special Stain
A
- Lamb (Loeffler Alkaline Methylene Blue) Stain
- Hiss Stain
- Fischer-conn stain
- Doner and Schaeffer-Fulton stain
- India Ink or nigrosine
7
Q
o Cold Method
o Oil based
o It does not utilize heat after addition of primary stain, which is oil based
o Acid fast bacilli will appear red on a green background
A
Kinyoun Stain
8
Q
- Stain bacteria, fungi and blood parasites in blood smears
- Together with carbol-fuchsin solution
- To visualize metachromatic granules
A
Lamb (Loeffler Alkaline Methylene Blue) Stain
8
Q
- A type of positive staining method that stains the capsule, slime layer and the bacterial cell with a brighter background.
- Dryer stain - stains the cell wall
A
Hiss Stain
9
Q
- Used to stain microorganisms with flagella
A
Fischer-conn stain
10
Q
- The endospore stain is a differential stain which selectively stains bacterial endospores
A
Doner and Schaeffer-Fulton stain
11
Q
- Capsule of the fungus Cryptococcus neoformans
A
India Ink or nigrosine
12
Q
- Used to grow microorganism
- Aqueous solution to which all necessary nutrients essential for growth of organisms are added
- Classified into 3 primary levels: physical, chemical composition and functional type
A
Culture media
13
Q
According to Physical State
A
- Liquid media
- Semi-solid media
- Solid-media
14
Q
- broth, milk or infusions, does not solidify at temperature above the freezing point
- no gelling agents such as gelatin or agar
- suited for propagation of large number of organisms, fermentation studies and other test
A
Liquid media
15
Q
- exhibit a clot like consistency at ordinary room temperature and contain agar at a concentration of 0.5% or less that allows thickening of the media without producing a firm substance
- soft consistency like custard
- best suited for culture of microaerophilic bacteria or for study of bacterial motility
A
Semi-solid media
16
Q
- contain solidifying agent such as 1.5%-2% agar
- used for isolation of bacteria and fungi or for determining the colony characteristic of the organism under study
- 2 forms: liquifiable (or reversible) solid media; non-liquifiable (non reversible) solid media
A
Solid-media
17
Q
According to Chemical Composition
A
- Synthetic media
- Non-synthetic media
18
Q
- Contain chemically defined substances which are pure organic and/or inorganic compounds
- Example: potato dextrose agar (pda), czapek-dox agar, oat meal agar (oma), corn meal agar (cma), beef peptone agar and nutrient agar.
A
Synthetic media
19
Q
- Contain at least one ingredient that is not chemically defined
- Example: extracts of animals, plants, yeast
- Can support the growth of more fastidious organisms
A
Non-synthetic media
20
Q
According to Functional Type
A
- General purpose media
- Enrichment media
- Selective media
- Differential Media
- Transport Media
- Anaerobic Media
21
Q
- Primary isolation of a broad spectrum of microbes and contain a mixture of nutrients that support the growth of both pathogenic and non pathogenic organisms
- Exanmple: peptone water, nutrient broth nutrient agar
A
General purpose media
22
Q
- Contain complex organic substances such as blood serum and special growth factors and are designed to increase the number of microorganisms without stimulating the rest of the bacterial population
A
Enrichment media
23
Q
- contains general nutrients with 5%-10% (by volume) blood added to blood agar base
A
Blood agar
24
Q
- complete lysis of rbc complete clearing around the colonies
A
Beta hemolysis
25
Q
- incomplete lysis of rbc, greenish discoloration
A
Alpha hemolysis
26
Q
- no hemolysis; no change in medium
A
Gamma hemolysis
27
Q
o Used for fastidious microorganism such as Haemophilus spp
o Heat is applied to lyse the RBC causing medium to turn brown
A
Chocolate Agar
28
Q
- difficult to grow in the laboratory because they have complex or restricted nutritional and/or environmental requirements.
A
Fastidious Bacteria
29
Q
- Contain one or more substances that encourage the growth of only a specific target microorganism and inhibit the growth of others
- Design to prevent the growth of unwanted contaminating bacteria or commensals so only target bacteria will grow
A
Selective media
30
Q
- contains antibiotics, used to isolation of neisseria
A
Thayer-martin agar
31
Q
- contains 10% nacl and used for isolation of staphylococcus aureus
A
Mannitol salt agar
32
Q
- Allow the growth of several types of microorganism
- Designed to show visible differences among certain groups of microorganisms
- Allow the growth of more than one target microorganism that demonstrates morphologic variations in colony morphology
A
Differential Media
33
Q
- promotes growth of gram negative bacteria, primarily those belonging to the family enterobacteriaceae
A
Macconkey’s agar
34
Q
- used to recover mycobacterium tuberculosis, made by incorporation of malachite green
A
Lowenstein-jensen medium
34
Q
- used for the isolation of fungi
A
Sarboraud’s dextrose agar
34
Q
- For organisms that cannot survive in the presence of oxygen and require reduced oxidation-reduction potential and other nutrients like Vit K and hemin
- They undergo boiling to remove dissolved oxygen
- Methylene blue or resarium is added as indicator of oxidation-reduction potential
- Example: Chopped meat and thioglycolate broth
A
Anaerobic Media
35
Q
- Used for clinical specimen that need to be transported to the laboratory immediately after collection
- Prevent drying of specimen and inhibit the overgrowth ofcommensal and
contaminating organisms - Charcoal is added to neutralize inhibitory factors
A
Transport Media
