Microscope SME Flashcards Set

Why are optical microscopes considered valuable tools for scientists?

They allow for the observation and study of tissues, cells, and organelles.

How does light travel through a microscope slide?

Light is directed through the thin layer of biological material supported on a glass slide.

What is the purpose of the eyepiece lens in an optical microscope?

It is used to view the magnified image of the specimen.

Which part of the microscope helps in focusing the image?

The coarse and fine focus knobs.

What is a coverslip used for in slide preparation?

To cover the specimen and prevent air bubbles.

What safety equipment should be worn when preparing microscope slides?

Gloves should be worn to prevent cross-contamination.

Why is it important to thin the tissue specimen?

So that light can pass through and the structures can be seen clearly.

What is the purpose of applying a stain to a specimen?

To make the structures visible as many tissues are naturally transparent.

What should be done to prevent dehydration of tissue on a microscope slide?

Add a drop of water beneath the coverslip.

What are the key components of an optical microscope?

Eyepiece lens, objective lenses, stage, light source, coarse and fine focus.

What is a graticule used for in microscopy?

To take measurements of cells in the field of view.

What must be done to calibrate a graticule?

It must be calibrated using a stage micrometer to determine the value of each graticule unit.

Why might specimens appear inconsistent in size on different slides?

Because cell structures are 3D and may be cut at different planes.

What is the effect of treating specimens during slide preparation?

It could alter the structure of the cells.

What kind of microscopy uses heavy-metal compounds for staining?

Electron microscopy.

What is differential staining in microscopy?

Staining specimens with multiple dyes to make different tissues visible.

What color does toluidine blue stain cells?

Blue.

What is the function of phloroglucinol in microscopy?

It stains cells red/pink.

What type of light microscopy dye absorbs specific colors of light?

Colored dyes.

What do specimens need to be treated with to make them rigid for slide preparation?

Formaldehyde as a preservative.

Why do chloroplasts not require staining?

They show up green, which is their natural color.

What must be done to ensure the specimen is visible under a microscope?

Stains must be applied to absorb specific colors of light.

What do you use to avoid air bubbles when preparing a slide?

Gently press down the coverslip after placing it.

What happens to images viewed through optical microscopes if the specimen is not thin enough?

Images may appear unclear or blurry.

What is the purpose of using a cryostat in microscopy?

To cut frozen specimens into thin slices.

What are some common problems when using an optical microscope?

Unclear images or cross-contamination.

What is the result of using a stage micrometer during calibration?

It allows you to determine the value of each graticule unit.

What can occur if calibration of the graticule is ignored?

Measurements taken can become arbitrary.

What is unique about electron microscopy in terms of color?

Electrons have no color, and any color in images is added afterward.

What do osmium tetroxide and ruthenium tetroxide do?

They are dyes used for staining in electron microscopy.

How does one prepare a slide using a liquid specimen?

Add a few drops using a pipette and cover with a coverslip.

Why must one be careful when using sharp objects to prepare solid specimens?

To avoid injury and to prevent staining from dye on skin.

What is the first step when using an optical microscope?

Start with the low power objective lens.

What technique can be used to measure the size of cells accurately?

Using a graticule calibrated with a stage micrometer.

What kind of light microscopy needs the specimen to absorb electrons?

Transmission electron microscopy (TEM).

Why are staining solutions important in microscopy?

They help make transparent tissues visible.

What should be done if the observed specimen is unclear under high magnification?

Switch to a lower power objective lens and use coarse focus.

What method is commonly used to dehydrate specimens before embedding?

A series of ethanol solutions.

What happens if cells are not properly stained?

Details of the cellular structures may not be visible.

Why do optical microscopes have limitations compared to other types of microscopes?

Their magnification power is lower, making some structures invisible.

What is the outcome of differential staining techniques?

It highlights various tissues within one specimen for better visibility.

How to avoid cross-contamination during slide preparation?

Always use gloves and clean tools.

What happens during the fixing process of a specimen?

The specimen is treated with chemicals to preserve its structure.