MICROSCOPY

38問 • 2年前

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is the most common method used both for the DETECTION of microorganisms directly in clinical specimens and for the CHARACTERIZATION of organisms grown in culture

Microscopy

Microscopy for diagnostic microbiology BACTERIA USES?

+ BRIGHT-FIELD MICROSCOPY + FLUORESCENCE MICROSCOPY +/- DARK FIELD MICROSCOPY

Microscopy for diagnostic microbiology FUNGI USES?

+ BRIGHT-FIELD MICROSCOPY + FLUORESCENCE MICROSCOPY

Microscopy for diagnostic microbiology PARASITES USES?

+ BRIGHT-FIELD MICROSCOPY + FLUORESCENCE MICROSCOPY +/- ELECTRON MICROSCOPY

Microscopy for diagnostic microbiology VIRUSES USES?

+ FLUORESCENCE MICROSCOPY +/- ELECTRON MICROSCOPY

visible light is passed through the specimen and then through a series of lenses that bend the light in a manner that results in magnification of the organisms present in the specimen

Bright field microcope

magnification - closest to the specimen

objective lens

magnification - nearest the eye

ocular lens

Example of magnification: objective lens

100x magnification x Ocular lens 10x magnification = 1000x magnification (or their actual size).

Lower magnifications (i.e., ?)

100× or 400×

(i.e., 100× or 400×)

Lower magnifications

To optimize visualization

Resolution

The extent to which DETAIL in the magnified object is maintained

Resolution

Without it everything would be magnified as an indistinguishable BLUR

Resolution

= for OPTIMAL detection and characterization of bacteria.

1000x + OIO

1000x + OIO= for _________ detection and characterization of bacteria.

OPTIMAL

third key component to light microscopy

Contrast

Contrast make objects stand _________ from the background

STANDOUT

make objects stand STANDOUT from the background

Contrast

is most commonly achieved by staining techniques

Contrast

- designed to provide maximum illumination and resolution when observing images

Kohler illumination

To visualize bacterial cells by light microscopy, a minimum concentration of _________ cells per 1 mL of specimen is required

10^5

utilizes beams of light passing through the specimen that are partially deflected by the different densities or thicknesses (i.e., refractive indices) of the microbial cells or cell structures in the specimen

Phase contrast microscopy

The greater the refractive index of an object, the more the beam of light is slowed, which results in decreased light intensity. These differences in light intensity translate into differences that provide contrast

Phase contrast microscopy

Principle: Certain dyes, called fluors or fluorochromes, can be raised to a higher energy level after absorbing ultraviolet (excitation) light. When the dye molecules return to their normal, lower energy state, they release excess energy in the form of visible (fluorescent) light.

Fluorescent microscopy

in the objective lens prevents the excitation wavelengths from DAMAGING the eyes of the observer

barrier filter

- DYE is used alone

Fluorochroming

- fluorescent dyes have been linked (conjugated) to specific ANTIBODY

Immunofluorescence

Fluorescent microscopy USED IN STAINS LIKE

AURAMINE CALCOFLUOR WHITE ACRIDINE ORANGE

Similar to phase contrast microscopy

Dark-Field Microscopy

the condenser does not allow light to pass directly through the specimen but directs the light to hit the specimen at an OBLIQUE angle

Dark-Field Microscopy

uses electrons instead of light to visualize small objects

Electron microscopy

allows, magnifications in excess of 100,000×

Electron microscopy

Electron microscopy allows, magnifications in excess of

100,000×

transmission electron microscope (TEM) - visualization of _________ structures

INTERNAL

- visualization of INTERNAL structures

transmission electron microscope (TEM)

Scanning electron microscope (SEM) - scan the _________ of objects and provides _________-dimensional views of surface structures

SURFACE; THREE

- scan the SURFACE of objects and provides THREE-dimensional views of surface structures

Scanning electron microscope (SEM)

other names parasitology

Yves Laure Pimentel · 70問 · 2年前

other names parasitology