How close together two objects can be and still be separated clearly in the image

How much detail can be seen

How distinct the specimen is from the background

Can be enhanced by staining either specimen (+) or background (-)

Can be enhanced using optical "tricks"

Use using the 100x objective of a light microscope to improve the resolution

It improves resolution because the oil has the same refractory index as glass preventing light from escaping by refracting causing all of the light to go into the objective

Type of light that microscope that illuminates the field of view evenly

Used in lab

Path of light: condensor, diaphragm, specimen, objective, ocular lens

Type of microscope that directs light toward the specimen at an angle, so that only light scattered by the specimen enters the objective lens; materials in the specimen stand out as bright objects against a dark background

Block light that goes thru specimen so it is illuminated thru the side

Like the dust example used in class

Phase Plate (=phase shifting element)

Used in interference microscope to separate incoming light into perpendicular polarized components and it then recombines incoming polarized light into the same polarization

See figure in notes

Special type of microscope used to observe cells that have been stained or tagged with fluoresent dyes

Uses excitation wavelengths as illuminating light, can see emission wavelength of fluorescently-labeled specimen

Type of microscope that focuses a laser beam to illuminate a given point on one vertical plane of a specimen; after successive regions and planes have been scanned, a computer can construct a 3-D image of a thick structure

Uses an aperture to shut out light from all but one focal plane of the object. Computer builds up 3-D object plane by plane

Light goes thru pinhole to detector

You can move pin hole to get multiple images at different planes to make an overall image

Type of microscope that directs a beam of electrons at a specimen; used to observe fine details of cell structure

Damages specimen after multiple uses

Requires that specimen to be sectioned and extensively fixed and stained

Less energetic electrons, less damage to specimen

Rotate baterium around source of electrons, takes images at multiple angles

See internal details in 3-D

At cold temps so specimen doesn't degrade

Type of scanning probe microscope that has a tip mounted so it can bend in response to the slightest force between the tip and the sample

Electric field is monitored at the tip of a nanotube probe

Field varies as probe is pushed over a surface

Can see atoms.

Staining technique that employs a basic dye to impart color to cells

Basic (+) dye attaches to (-) phospholipid head groups

All cells stained the same color

Type of staining procedure used to distinguish one group of bacteria from another by taking advantage of the fact that certain bacteria have distinctly different chemical structures in some of their components

More than one stain used

Staining technique that divides bacteria into two groups, Gram (+) or Gram (-), on the basis of color; among bacteria, the staining reaction correlates well with cell wall structure (thickness)

Pink = thin (gram -)

Purple = thick (gram +)

1st purple, then alcohol decolorizes thin, 2nd pink identifies thin

A procedure used to stain certain microorganisms, particularly members of the genus Mycobacterium, thatdo not readily take up dyes used in microbiology

Differentiates based on waxy coating impervious to acidified alcohol

Red = acid-fast, Blue = not

1st red, 2nd decolorize w/acidified alcohol, 3rd blue not acid fast