HEM Microscopy

Question 1

Define resolution

Answer 1

the minimum distance a microscope can actually differentiate two points without blurring them together

Question 2

Define resolving power

Answer 2

As resolving power increase, the VALUE for resolution DECREASES

NOTE: distance between two objects becomes smaller = resolution “gets better”

Question 3

Calculate Empty magnification

Answer 3

Empty magnification> 1000xNA

Increased magnification of an object WITHOUT increased resolving power/ detail (when image becomes fuzzy)

Question 4

Calculate resolution

Answer 4

2NA(obj)

obj= objective lens
cond= condenser

Question 5

Greatest detail (greater resolving power, smaller value for resolution) is seen in shorter or longer wavelengths ?

Answer 5

Shorter wavelengths

Question 6

As Numerical Aperture increases, resolution becomes __ and resolving power __.

Answer 6

As Numerical Aperture increases, resolution becomes A SMALLER NUMBER and resolving power INCREASES

Question 7

What kind of image is formed by a microscope ?

Answer 7

A VIRTUAL image; object is before the focal point
- stays inverted; not flipped by ocular

Question 8

What is the Numerical Aperture ?

Answer 8

measure of a len’s light-gathering potential
- depends on lens aperture AND refractive index of air/ oil

Question 9

What is the purpose of immersion oil ?

Answer 9

has a high refractive index
increases NA and resolving power

Question 10

Calculate total magnification

Answer 10

take the power of the objective (4X, 10X, 40x) and multiply by the power of the eyepiece, usually 10X