Microscopy

Question 1

Describe what microscopy is

Answer 1

Microscopy is the science of using microscopes to view small objects that cannot be seen with the naked eye, such as cells, tissues, and microorganisms.

Question 2

Identify the two main types of microscopes

Answer 2

Light microscope and electron microscope.

Question 3

Explain how a light microscope works

Answer 3

A light microscope uses visible light to illuminate a specimen. The light passes through the specimen, is magnified by the objective lens, and further magnified by the eyepiece lens, allowing the observer to see the image.

Question 4

State the maximum magnification and resolution of a light microscope

Answer 4

The magnification is up to 1000x, and the resolution is limited to ~200 nm.

Question 5

Give examples of specimens suitable for observation with a light microscope

Answer 5

Live cells, bacteria, and simple tissues.

Question 6

Explain why stains are used in light microscopy

Answer 6

Stains are used to improve contrast and highlight specific structures within cells or tissues, making them easier to see under the microscope.

Question 7

List three stains and their effects

Answer 7

Methylene Blue: Stains nuclei blue.
Leishman’s Stain: Stains blood cells pink and white blood cell nuclei blue.
Hematoxylin/Eosin: Stains nuclei blue and cytoplasm pink.

Question 8

Calculate the total magnification if the objective lens is 40x and the eyepiece lens in 10x

Answer 8

Total magnification = 40x × 10x = 400x.

Question 9

Describe the function of the condenser in a light microscope

Answer 9

The condenser focuses light from the illuminator onto the specimen, ensuring even illumination and better image quality.

Question 10

Explain the role of the iris diaphragm

Answer 10

The iris diaphragm controls the amount of light reaching the specimen, which affects the contrast and brightness of the image.

Question 11

Distinguish between the functions of the coarse focus knob and fine focus knob

Answer 11

The coarse focus knob brings the specimen into general focus, while the fine focus knob adjusts the image precisely, especially at higher magnifications.

Question 12

Outline the steps involved in specimen preparation for light microscopy

Answer 12

The steps include fixation, dehydration, clearing, embedding, sectioning, staining, and mounting.

Question 13

Describe the purpose of fixation in specimen preparation

Answer 13

Fixation preserves the specimen in a life-like condition with minimal distortion, making it suitable for examination.

Question 14

Explain why sectioning is important in microscopy

Answer 14

Sectioning produces thin slices of the specimen, allowing light to pass through, which is necessary for clear visualization under the microscope.

Question 15

State the formula for calculating magnification

Answer 15

Magnification = Image size / Actual size of the specimen.

Question 16

Describe how a light microscope is used to observe a blood sample

Answer 16

A blood sample is placed on a glass slide, stained to highlight specific structures (e.g., Leishman’s stain), and then observed under a light microscope. The light passes through the sample, which is magnified by the objective and eyepiece lenses, allowing detailed visualization of blood cells.

Question 17

Explain the importance of staining in light microscopy when examining tissues

Answer 17

Staining increases contrast, making specific structures (e.g., nuclei or cytoplasm) more visible. This allows for better identification of cell components and any abnormalities, which aids in diagnosis and research.

Question 18

Identify the part of the microscope responsible for adjusting the amount of light reaching the specimen

Answer 18

The iris diaphragm

Question 19

Explain why using a blue light filter can improve resolution in a light microscope

Answer 19

blue light has a shorter wavelength than white light, allowing for finer resolution and greater detail in the observed image.

Question 20

Explain how microscopy can aid in diagnosing diseases

Answer 20

Microscopy allows for the observation of cells and tissues at a microscopic level. Abnormalities, such as changes in cell size, shape, or structure, can indicate diseases like cancer or infections.

Question 21

Identify two advantages of using a light microscope in healthcare

Answer 21

1. It allows for the observation of live specimens, enabling dynamic studies of cell behavior.
2. It is cost-effective and widely available, making it accessible for routine clinical use.

Question 22

Explain how staining blood samples can help in diagnosing anemia

Answer 22

Staining allows for the identification of red blood cells’ size, shape, and count. Abnormalities, such as smaller or fewer red blood cells, can indicate anemia.

Question 23

Outline how a health professional might prepare a tissue sample for microscopic examination

Answer 23

1.Fixation: Preserve the tissue.
2.Dehydration: Remove water.
3.Clearing: Make tissue transparent.
4.Embedding: Support for cutting.
5.Sectioning: Cut thin slices.
6.Staining: Enhance contrast.
7.Mounting: Protect for viewing.