Microbiology Ch 2

Front 1

Resolution

Back 1

smallest distance by which two objects can be separated and still be distinguished.High resolution is closer to you, low resolution would be further.

Front 2

Detection

Back 2

the ability to determine the presence of an object. Don't necessarily need a microscope for detection.

Front 3

Magnification

Back 3

the increase in the apparent size of an image in order to resolve smaller separations between objects. Sometimes magnification doesn't equal resolution ex when you see something but its blurry.

Front 4

Bright Field Microscope

Back 4

Conventional microscope
Dark objects against a light filled field

Front 5

What is use of immersion oil in microscopy

Back 5

Light rays are bent when they pass through the air. They don't bend as much when passing through the slide and the oil, thus more light from the speciment reaches the objective when oil is used.

Front 6

What is used to improve resolution and contrast?

Back 6

Fixation and staining

Front 7

Single stain - basic dyes

Back 7

Crsystal Violet
Methylene blue
Safranin

Front 8

Single stain - Acidic Dyes

Back 8

Congo red
Eoslin
Nigrosin

Front 9

What is differential stain

Back 9

Use of 2 dyes for staining and counterstaining
Most commonly used method

Front 10

Differential Stain - Gram Stain

Back 10

Bacteria are divided into 2 groups - gram positive and gram negative

Front 11

Gram Staining Procedure

Back 11

1. Add methanol to fix cells to surface and air dry.
2. Add crystal violet stain
3. Add iodine, which binds stain to gram-positive cells.
4. Wash with ethanol
5. Add safranin

Front 12

Dark-Field Microscope

Back 12

Permits diversion of light rays and illumination, from the side so that details appear light against a dark background as opposed to light passing straight through it.

Front 13

Phase - Contrast Microscope

Back 13

Capable of making extremely thin or transparent samples and specimens visible by use of contrast level.

Ex: Allows you to see hosts infected by spores.

Front 14

Interference Microscope

Back 14

creates image by using the difference between an interfering beam unmodified by the specimen and an otherwise identical beam that illuminates it. Beam splitter divides light into two paths, one of which passes through the specimen while the other one bypasses it. When the two beams are combined, the resulting interference then reveals the structure of the specimen.