Lab Practical #1 Review

Microincinerator

Pipette pump

Inoculating loop

Inoculating needle

Calibrated pipette

Quebec colony counter

Incubator

Biohazard waste can

Biological safety cabinet

Water bath

Autoclave

Personal Protective Equipment (PPE)

Disposable lab coat, goggles, gloves, closed toe shoes

Ocular lens

Identify the part of the microscope

10x

Magnification of this lens

Rotating nosepiece

Identify the part of the microscope

Objective lenses

Identify the set of lenses

Mechanical stage

Identify the part of the microscope

Iris diaphragm

Identify the part of the microscope

Condenser

Identify the part of the microscope

Light source

Identify the part of the microscope

Light switch

Identify the part of the microscope

Arm

Identify the part of the microscope

Binocular head

Identify the part of the microscope

Coarse adjustment knob

Identify the part of the microscope

Coarse adjustment knob

Identify the part of the microscope

Fine adjustment knob

Identify the part of the microscope

Fine adjustment knob

Identify the part of the microscope

Condenser knob

Identify the part of the microscope

Dimmer knob

Identify the part of the microscope

40x (4x scanning low power objective lens x 10x ocular lens)

Calculate total magnification when using the circled objective lens

100x (10x low power objective lens x 10x ocular lens)

Calculate total magnification when using the circled objective lens

400x (40x high power objective lens x 10x ocular lens)

Calculate total magnification when using the circled objective lens

1000x (100x oil immersion objective lens x 10x ocular lens)

Calculate total magnification when using the circled objective lens

Bacterial culture

This is a method of multiplying bacteria by letting them reproduce in predetermined culture media under controlled laboratory conditions

Inoculation, Incubation, Isolation, Inspection, Identification

5 I's of culturing and identifying microorganisms

Culture media

A solution containing nutrients for bacteria to grow

Broth

Liquid medium

Agar

A solidifying agent for media made from seaweed

Aseptic technique

Procedures that are used to prevent contamination of a person, object, or area by microorganisms

Streak plate

A dilution method to spread a colony or loopful of bacteria across a plate to be able to observe isolated colonies

B

Which plate demonstrates a good streak plate?

2

How many species of bacteria are on this streak plate?

Colony Characteristics

Size, Pigment, Form, Margin, Elevation

Form

What bacterial colony characteristic do these terms describe?

Margin

What bacterial colony characteristic do these terms describe?

Elevation

What bacterial colony characteristic do these terms describe?

Circular

Describe the form (shape) of this colony

Rhizoid

Describe the form (shape) of this colony

Yellow

Describe the pigment of this colony

Red

Describe the pigment of this colony

Lobate

Describe the margins of this colony

Entire

Describe the margins of this colony

Flat

Describe the elevation of this colony

Convex

Describe the elevation of this colony

Negative stain

Dye has a negative charge; the background around the bacteria or other cells is stained, and the cells are unstained

Positive stain

Dye that has a positive charge; stains the bacteria or structure

Simple stain

A bacterial smear is stained with a single reagent.

Differential stain

Uses 2 or more dyes to differentiate between bacterial species or distinguish between structures of an organism

Crystal violet

Primary stain in the Gram staining procedure; counterstain in the capsule staining procedure

Gram's iodine

Mordant in the Gram staining procedure

95% Ethanol

Decolorizer in the Gram staining procedure

Safranin

Counterstain in the Gram staining procedure; counterstain in the endospore staining procedure

Carbol fuchsin

Primary stain in the acid fast staining procedure

Tergitol

Is added to carbol fuchsin in the Kinyoun acid fast stain procedure to help the cell take up the stain

Acid alcohol

Decolorizer in the acid fast staining procedure

Methylene blue

Counterstain in the acid fast staining procedure

Malachite Green

Primary stain in the spore staining procedure

Nigrosin

Reagent used for negative stain; primary stain in the capsule staining procedure

Endospores

Identify the bacterial structures here that stain green with malachite green

Bacillus and Clostridium

Identify 2 genera that have endospores

Mycobacterium

Identify the genus of bacteria that stain red (acid fast) in the acid fast stain

Capsules

Identify the white structures

Gram negative cocci in pairs

Identify the gram reaction, shape and arrangement

Gram positive cocci in chains

Identify the gram reaction, shape and arrangement

Gram positive cocci in clusters

Identify the gram reaction, shape and arrangement

Gram negative bacilli

Identify the gram reaction and shape

Gram positive bacilli

Identify the gram reaction and shape

Crystal violet, Gram's Iodine, 95% Ethanol, Safranin

List in order the reagents used in the Gram stain

Carbol fuchsin, Acid Alcohol, Methylene blue

List in order the reagents used in the acid fast stain

Malachite Green, Water, Safranin

List in order the reagents used in the spore stain

Nigrosin, Crystal Violet

List in order the reagents used in the capsule stain

Water will enter the cell and cause it to swell and possibly lyse.

Explain why bacterial cells should not be placed in pure distilled water

30-300

When performing the standard plate count, a countable plate has a range of __________ colonies

TFTC (too few to count)

If you observe

TNTC (too numerous to count)

If you observe >300 colonies on a plate when doing the standard plate count, what do you report?

Quebec colony counter

What is the name of this instrument used in the standard plate count?

27,300,000 or 2.73 x 10^7

Calculate the number of CFU/ml in the original sample:
273 colonies on the plate; 1 ml. plated of a 1:100,000 dilution

TNTC (too numerous to count)

Calculate the number of CFU/ml in the sample:
353 colonies on the plate; 1 ml. plated of a 1:10,000 dilution

680,000,000 or 6.8 x 10^8

Calculate the number of CFU/ml in the sample:
68 colonies on the plate; 0.1 ml. plated of a 1:1,000,000 dilution

TFTC (too few to count)

Calculate the number of CFU/ml in the sample:
27 colonies on the plate; dilution factor = 1,000,000

B

Which of the following plates for the standard plate count is countable?

Selective and Differential

Classification of Eosin Methylene Blue agar (EMB)

Selective and Differential

Classification of MacConkey agar (MAC)

Selective and Differential

Classification of Mannitol Salt Agar (MSA)

Enriched and Differential

Classification of Blood Agar (BA or BAP)

Gram negative bacilli; inhibits Gram positive bacteria

Which type of organisms grow on MacConkey (MAC) agar?

A and B

Which organism(s) shown on this MAC plate are lactose fermenters?

Staphylococci (salt tolerant)

Which type of organisms grow on Mannitol Salt Agar (MSA)?

B

Which organism on this MSA plate is a mannitol fermenter?

Gram negative bacilli; inhibits Gram positive bacteria

Which type of organisms grow on Eosin Methylene Blue agar (EMB)?