Microscope

Question 1

What is the most common type of microscope used in a clinical laboratory?

Answer 1

binocular compound microscope

binocular - 2 pieces
compound - uses a combination of lenses to generate an image

Question 2

What is a binocular compound microscope used for?

Answer 2

to evaluate blood, urine, semen, bodily fluids, feces and other specimens

Question 3

How many microscopes should there be in a clinical laboratory (ideally)?

Answer 3

2 - one for parasitology and another for hematology + cytology

Question 4

Why should there be a separate microscope for parasitology samples?

Answer 4

Reagents are used to examine parasitology slides which can be corrosive over time and cause damage

Question 5

What are the parts to a microscope?

Answer 5

eye pieces (ocular lenses), nosepiece, objective lenses, stage, slide holder, travel knobs/mechanical stage knobs, fine adjustment knob, course adjustment knob, condenser, diaphragm, light source

Question 6

What are ocular lenses?

Answer 6

• first point of magnification
• 10x power of magnification
• Can be focused for the individual
• Can be moved closer together or farther apart
• Some contain a small arrow to “point” to things
• Some contain a reticle

Question 7

What is a reticle?

Answer 7

• a scale used to measure objects

- to use to determine the size of the specimen (esp. in parasitology)

Question 8

what are objective lenses?

Answer 8

• second point of magnification

- contains 3-4 objectives typically, they revolve around the nosepiece

Question 9

4x magnification

Answer 9

scanning

red

Question 10

10x magnification

Answer 10

low power

yellow

Question 11

40x magnification

Answer 11

high dry

blue

Question 12

100x magnification

Answer 12

oil immersion

white/grey

Question 13

How to calculate total magnification

Answer 13

Total Magnification = Ocular lens power X Objective lens power

Question 14

How does an object appear when looking through a microscope?

Answer 14

the object will appear upside down and reversed

the right side is seen on the left
the left side is seen on the right

Question 15

The movement of the mechanical stage is _______.

Answer 15

reversed

when moving the stage to the left, the object appears to the move to the right, vice versa

Question 16

what is the microscope stage?

Answer 16

• this is where the slide is placed
• there is an arm to hold the slide
• there are control knobs that helps to move our slide back and forth, to use to scan
• some stages will have markings which allows you to mark and take note of where the slide is, both vertically or horizontally

Question 17

What are the adjustment knobs on a microscope?

Answer 17

• these knobs move the stage towards or away from the objective lenses
• use to focus the specimen

Question 18

what are the two types of adjustment knobs?

Answer 18

coarse adjustment knob

fine adjustment knob

Question 19

coarse adjustment knob

Answer 19

moves the stage the most
brings the specimen into focus
use this w/ your smaller power objectives

Question 20

fine adjustment knob

Answer 20

fine tunes and increases the details of the specimen
can be used w/ any of the objectives
moves the stage with the slightest possible shift

Question 21

condenser

Answer 21

• sits below the stage (substage)
• it has 2 lenses that focus light from the light source onto the specimen being viewed
• light is focused by raising or lowering the condenser
• typically best if the condenser is kept at its HIGHEST position (closest to the specimen)
• W/O this - there are halos and fuzzy rings that can appear around the specimen

Question 22

Diaphragm part of the microscope

Answer 22

• typically an iris type
• controls the amount of light that is directed up at the slide
• more light typically clarifies the specimen
• lower light will increase the contrast (best for identifying eggs in parasitology)

Question 23

Light source of a microscope

Answer 23

• found at the base
• should be on a “dimmer” like switch –> meaning we should be able to control the intensity of the light and it depends on what your looking at

Question 24

What are some ways to care and maintenance the microscope?

Answer 24

1) use only HIGH quality lens paper to clean the objective lenses (if not, scratches can form)
2) avoid excess oil when using the 100x objective
3) never use oil on any other objective
4) use lens cleaning solution (or methanol) to remove excess oil + clean objectives
5) place/store away from sunlight, drafts, liquid, and avoid excess heat & humidity