Microscope Anatomy and Operation Guide

How should a microscope be held when being carried from a cabinet?

With one hand holding the arm and the other hand under the base.

To avoid a tripping hazard, what should be done with the microscope power cord when it is plugged in?

It should be unwound from the back and kept away from walking paths.

At what number should the ocular lenses be aligned before beginning observation?

The number 64 should line up with the white line on the lens.

Which objective lens should be in place when first setting up or finishing with the microscope?

The lowest power objective lens (typically 4×- low power).

What is the initial position of the stage when starting to focus on a specimen?

The stage should be at its highest position.

What component is used to adjust the amount of light passing through a specimen on the stage?

The diaphragm (or iris diaphragm).

When using the 4× objective, which knob is used to bring the specimen into general focus?

The coarse focus knob.

Why is the lowest power objective used first when searching for a specimen?

It provides the largest field of view to locate the specimen easily.

When moving from the 10× to the 40× objective, which focus knob should be used exclusively?

The fine focus knob.

How is the total magnification of a microscope image calculated?

By multiplying the power of the ocular lens by the power of the objective lens.

What is the total magnification if the ocular lens is 10× and the objective lens is 40×?

400x (high dry)

What is the only material that should be used to clean microscope lenses?

Lens paper.

If a high-power image appears blurry like it is coated in Vaseline, what action should be taken?

Clean the lens with lens paper soaked in lens cleaner.

In a wet mount slide preparation, how should the coverslip be lowered to avoid air bubbles?

At an angle, touching the edge of the liquid first before being slowly lowered.

When storing a microscope, where should the stage be positioned?

Centered with the slide holder moved to the left.

What does the acronym OSHA stand for?

Occupational Safety and Health Administration.

The practice of treating all human blood and body fluids as if they are known to be infectious is called _____.

Universal Precautions (now called standard precaution)

According to OSHA, what are 'bloodborne pathogens'?

Pathogenic microorganisms in human blood that can cause disease, such as HBV or HIV.

Engineering Controls

Devices that isolate or remove a bloodborne pathogen hazard from the workplace, such as sharps disposal containers.

What are the three traditional components of the 'chain of infection'?

The source, the host, and the mode of transmission.

What is considered the single most effective way to break the chain of infection in a laboratory?

Hand washing

How long should hands be vigorously washed to ensure disinfection?

At least 20 seconds (the time it takes to sing 'Happy Birthday' twice).

When rinsing hands during lab cleanup, why should they be held in a downward position?

To prevent the contamination of the wrists from the hands.

Where should used needles, broken glass, and scalpels be disposed?

In a puncture-proof, labeled sharps container.

Under what specific condition may a lab worker recap a needle?

Only if using a mechanical device or machine for recapping.

When mixing chemicals, what is the correct order for combining acid and water?

Always add the acid to the water.

If a chemical spills on the skin, what is the required first aid before seeking medical attention?

Flush the area with running water for at least 15 minutes.

What quadrant of the NFPA hazardous material diamond indicates a 'health hazard'?

The blue (left) quadrant.

What quadrant of the NFPA diamond indicates a 'fire hazard' or flammability?

The red (top) quadrant.

In the NFPA Diamond, what does the yellow quadrant represent?

Reactivity (instability) hazard.

What is the grading scale used for the quadrants in an NFPA safety symbol?

0 (minimal hazard) to 4 (severe hazard).

Which document provides thorough details on a chemical's physical characteristics, reactivity, and emergency first aid procedures?

The Material Safety Data Sheet (MSDS).

Which type of hazard includes environmental factors like radiation, extreme temperatures, and constant loud noise?

Physical hazards.

Repetitive tasks like pipetting or working at an improperly adjusted workstation are examples of _____ hazards.

Ergonomic

What is the primary rule when helping a victim of electric shock in the lab?

Never touch the person or the equipment involved directly; turn off the power source first.

In fire safety, what does the acronym 'RACE' stand for?

Rescue, Alarm, Contain, Extinguish.

What acronym describes the steps for operating a fire extinguisher?

PASS (Pull, Aim, Squeeze, Sweep).

Which fire classification involves flammable liquids like grease or gasoline?

Type B (mnemonic: 'Basa' or liquid).

Which fire classification involves electrical equipment and motors?

Type C (mnemonic: 'Corriente' or current).

What concentration of sodium hypochlorite is typically used for the daily disinfection of laboratory sinks?

1:5 or 1:10 dilution.

Which color-coded waste container is designated for non-infectious dry waste like paper?

Black.

Which color-coded waste container is used for infectious and pathological waste such as cotton with blood?

Yellow.

In a clinical lab, what is the proper way to dispose of biological urine samples?

By pouring them into a laboratory sink and flushing with water.

What device provides ventilation to protect lab workers from inhaling hazardous chemical vapors?

A fume hood.

Why should long hair be tied back and dangling jewelry removed in the laboratory?

To prevent them from getting caught in equipment or touching hazardous materials.

When lifting heavy objects in the lab, what is the recommended posture to avoid back injury?

Bend the knees rather than the waist.

What is the function of the 'revolving nosepiece' on a microscope?

It allows for easy switching between different objective lenses.

Why shouldn't you look through the ocular lens while moving the stage up with the coarse adjustment knob?

To prevent the slide from crashing into the objective lens.

What is the purpose of the 'condenser lens' located just below the stage?

To focus light from the lamp onto the specimen.

How should a used paper towel be used after hand washing to maintain hygiene?

To turn off the faucet before discarding the towel.

Stressors caused by increased workload or workplace harassment are categorized as _____ hazards.

Work organization

What specific safety equipment should be used to protect the eyes from splashes or aerosols?

Goggles or face shields.

What kind of fire involves ordinary combustibles like cloth, paper, or wood?

Type A.

What is the name of the rotating disc under the stage that varies light intensity projected into the slide?

The diaphragm.

Which objective lens typically requires the use of a special oil to improve resolution?

The 100× (oil immersion) lens.

When troubleshooting a microscope, why is it recommended to move the slide slightly while focusing?

Because human eyes detect motion better than stationary objects.

What does the 'A' in the PASS acronym for fire extinguishers stand for?

Aim the nozzle at the base of the fire.

According to the CDC, when are laboratory incidents most likely to occur?

When staff fail to adhere to established safe practices.

Which type of hazard includes x-rays and microwaves?

Physical hazards (radiation).

How should lab gowns with cuffs be worn to ensure proper protection?

Completely buttoned with gloves pulled over the cuffs.

What are the two objective lenses that is mostly used in Hematology?

40x and 100 x (high dry and oil immerse)