Lecture 20

Question 1

2 ways to perform an agglutination test

Answer 1

• unknown cells with specific antibody

- known cells with unknown serum

Question 2

diffusion assay

Answer 2

A ring of wells is cut into an agar plate, antibodies and antigen diffuse through the agar and will form visible precipitate between the wells. antibodies/serum or protein sample goes in the center

Question 3

intersecting precipitin

Answer 3

non-identity

Question 4

spur (wavelength looking thing)

Answer 4

partial identity

Question 5

arc

Answer 5

identity

Question 6

Describe immunofluorescent staining

Answer 6

• cells placed on slides
• cells fixed using paraformaldehyde or mathanol/acetone and rinsed
• cells permeabilized using dilute detergent
• cells blocked to reduce nonspecific binding
• primary antibody added and washed
• secondary fluorescent antibody added and washed

Question 7

standard fluorescent microscopy

Answer 7

whole image is illuminated and out-of-focus light makes the in-focus image fuzzy; cheap but fuzzy and photodamage

Question 8

confocal fluorescent microscopy

Answer 8

whole image is illuminated and out-of-focus light is blocked; good resolution but photodamage

Question 9

two-photon fluorescent microscopy

Answer 9

less energetic light is used (infrared) and 2 photons must hit the dye simultaneously to excite it; lower photodamage and better tissue penetration but costly and inferior resolution to confocal

Question 10

Are circular or linear chromosomes more complex?

Answer 10

linear due to end-replication problems

Question 11

plasmids

Answer 11

small rings of DNA