Microscopy and Staining Flashcards
What type of microscopy uses a dark background with a light specimen?
Dark-field microscopy
Dark-field microscopy is useful for observing thin or pale specimens.
What microscopy technique allows us to see different phases of specimens and increases resolution?
Phase contrast microscopy
Phase contrast microscopy enhances the visibility of transparent specimens.
What is the purpose of differential interference microscopy?
It is a type of phase contrast microscopy
Differential interference microscopy provides enhanced contrast for transparent specimens.
What microscopy method uses fluorescent tags to visualize parts of specimens?
Fluorescent microscopy
Fluorescent microscopy is often used in biological studies to highlight specific structures.
What is the main advantage of confocal microscopy?
Greatly increases resolution and blocks out-of-focus light
Confocal microscopy allows for detailed imaging of specimens at various depths.
What type of microscopy uses electrons to visualize specimens?
Electron microscopy
Electron microscopy, including scanning and transmission types, can visualize incredibly small specimens.
Define resolution in microscopy.
The closest distance we can see two distinct objects
Resolution determines how well two objects can be distinguished from each other.
What does empty magnification refer to?
Increasing magnification without increasing resolution
Empty magnification can lead to a blurry image that does not reveal more detail.
What is a simple stain?
Using one stain to visualize anything that’s there
Simple staining is a basic technique for observing cellular structures.
What is the purpose of differential stains?
Differentiating between different species and structures
Differential staining techniques are often used in microbiology to identify specific bacteria.
What does Gram staining identify?
Types of bacterial cell walls
Gram staining categorizes bacteria into Gram-positive (purple) and Gram-negative (pink).
What does an endospore stain look for?
Presence of endospores
Endospore staining typically shows red and green colors.
What does acid-fast staining detect?
Presence of mycolic acid
Acid-fast staining results in blue and pink coloration, useful for identifying certain bacteria.
What is the focus of flagellar staining?
Presence of flagella
Flagellar staining highlights the flagella of bacteria for identification.
What does capsule staining look for?
Presence of capsules
Capsule staining often uses negative stains to visualize the surrounding capsule structure.
What kind of stain is used on microbes, acidic or basic?
Basic stain
Basic stains are positively charged and bind to negatively charged cellular components.
What is the first step in Gram staining?
Primary Stain - crystal violet
Crystal violet is the first reagent applied in the Gram staining procedure.
What is the second step in Gram staining?
Mordant - iodine
Iodine acts as a mordant to fix the crystal violet stain within the cells.
What is the third step in Gram staining?
Decolorizer - acetone/alcohol
The decolorizer differentiates between Gram-positive and Gram-negative bacteria.
What is the final step in Gram staining?
Counterstain - safranin
Safranin stains the decolorized Gram-negative bacteria pink.
