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Flashcards in Chapter 2: Tools of the Laboratory Deck (55)
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1

The Five I's

Inoculation Incubation Isolation Inspection Identification

2

Culture

the propagation of microorganisms with various media

3

Medium

a nutrient used to grow microorganisms outside their natural habitat

4

Inoculation

the implantation of microorganisms into or onto culture media

5

Usual incubation temperatures

between 20°C and 40°C

6

Pure Culture

container of medium that grows only a single known species

7

Mixed Culture

Contains two or more identifiable species

8

Contaminated Culture

Was once pure or mixed, but has since been contaminated; can't identify all the organisms

9

Physical States of Media

liquid semisolid solid (can be converted to liquid) solid (cannot be liquefied)

10

Agar

complex polysaccharide from the alga Gellidium; liquefies at 100°C and solidifies at 42°C and can be poured in liquid form that will not harm the microbe or the handler

11

General Purpose Media

Grows a broad spectrum of microbes; complex; Nutrient agar, broth, brain-heart infusion, & TSA

12

Selective Media

Contains one or more agents that inhibit growth of certain microbes but not others; for samples containing dozens of different species (saliva, skin, water, soil)

13

Enriched Media

Contains complex organic substances; for growing certain species (fastidious microbes); Blood agar, Chocolate agar

14

Differential Media

Allows multiple types of microorganisms to grow; causes different reactions (dyes make microorganisms easily identifiable)

15

Transport Media

Used to maintain and preserve specimens that have to be held for a period of time before clinical analysis; also used to sustain species that die quickly

16

Reducing Media

Contains sodium thioglycollate or cystine that absorbs oxygen or slows the penetration of oxygen; grows anaerobic bacteria or determines oxygen requirements of isolates

17

Carbohydrate Fermentation Media

Contains sugars that can be fermented (converted to acids) and a pH indicator to show this reaction; identifies bacteria and fungi

18

Streak Plate

Easy and effective; method of choice

19

Loop Dilution

Allows colonies to grow deep in the solution, not just on the surface

20

Viruses measurements

between 20 – 800 nm

21

Smallest bacteria measurements

200 nm

22

Protozoa and Algae measurements

3-4 mm

23

Objective Lens

closest to the specimen, forms the initial image called the real image

24

Ocular Lens

forms the second image called the virtual image that will be received by the eye and converted to the retinal and visual image

25

Resolution

the capacity of an optical system to distinguish or separate two adjacent objects or points from one another.

26

Human eye can resolve objects that are no closer than___________apart

0.2 mm

27

Oil Immersion Lens

uses oil to capture light that would otherwise be lost to scatter which in turn increases resolution; oil immersion lens can resolve images that are at least 0.2 μm in diameter and at least 0.2 μm apart

28

Bright-field Microscope

Forms its image when light is transmitted through the specimen; produces image that is darker than the surrounding illuminated field.

29

Dark-field Microscope

Puts a "block" on a bright-field microscope that blocks all light from entering the objective lens except peripheral light; creates image of brightly illuminated specimens surrounded by a dark field

30

Phase-Contrast Microscope

Transforms subtle changes in light waves passing through specimen into differences in light intensity (different parts of specimen have different densities); best for internal detail