Light Microscopy (Lecture 5)

Question 1

What technique is used to determine if someone is iron deficient and how?

Answer 1

centrifugation is a good technique because the red blood cells will be relatively lower than the norm (>45%)

Question 2

______ is a machine flows cells past a laser beam that measures the light that they scatter and the fluorescence that they emit

Answer 2

Flow cytometry

Question 3

What does FACS stand for?

Answer 3

— Fluorescence-activated cell sorter (FACS) thats based on flow cytometry

Question 4

How does FACS work?

Answer 4

The stream of droplets then passes through two plates that generate an electric field proportional to the fluorescence detected from the cell in the droplet.

The cells are separated based on their charges

Question 5

True or False: You can use antibodies bound to white blood cells and there special cell-surface proteins to separate them from red blood cells.

Answer 5

True

Question 6

______ are monoclonal antibodies that all bind to the same epitope.

Answer 6

Monovalent affinity

Question 7

______ are only a single epitope is recognized.

Answer 7

Monoclonal antisera

Question 8

How does monoclonal antibody production work?

Answer 8

Mutant mouse cells and spleen cells are fused used viral glycoproteins

Only the fused cells will survive on the medium

Screen hybridomas for production of desired antibody

Question 9

True or False: Hybridoma cells produce monoclonal antibodies that bind one antigen epitope and are used for basic research and therapeutics.

Answer 9

True

Question 10

______ approach starts with assays (e.g. add potential drugs to cultured cells and look for a desirable change in look)

Answer 10

Phenotype-based approach

Question 11

______ approach starts with target selected from a biochemical pathway (enzyme, receptor, etc.) linked to specific disease state

Answer 11

Target-based

Question 12

In light microscopy, what is the resolution limited by?

Answer 12

Light wavelength

Question 13

How is resolution enhanced?

Answer 13

Enhanced by exploiting differences in refractive index, staining, or fluorescent labeling specific components with dyes or fused fluorescent proteins

Question 14

______ is the ability to

distinguish between two very closely positioned objects

Answer 14

Resolution

Question 15

In the resolution equation, α is known as?

Answer 15

the angular aperture, or half-angle, of the cone

of light entering the objective lens from the specimen

Question 16

In the resolution equation, N is known as?

Answer 16

the refractive index of the medium between the specimen and the objective lens (i.e., the relative velocity of light in the medium compared with the velocity in air)

Question 17

In the resolution equation, λ is known as?

Answer 17

the wavelength of the incident light

Question 18

What type of microscopy would be used best for viewing the thickness of an object?

Answer 18

Differential-Interference-Contrast (DIC)

Question 19

Other than resolution, what is the other main limitation to light microscopy?

Answer 19

Light must be able to pass through the sample

Question 20

Histological samples are often stained with what to chemicals?

Answer 20

Hematoxylin and eosin

Question 21

______ binds to basic amino acids (lysine and arginine) on many different kinds of proteins whereas ______ binds to acidic molecules (such as DNA and side chains of the amino acids aspartate and glutamate).

Answer 21

Hematoxylin , eosin