Ab-Ag Interactions

Question 1

Ab AVIDITY

Answer 1

Strength of multivalent antiserum to multivalent Ag
Most Ags have numerous EPITOPES and are also mulltivalent –> Multiple Ab species that can bind to several of these epitopes
NOT TESTED ON THIS WORD

Question 2

Absorption

Answer 2

The use of cross reacting material to remove the activity that causes the cross reactivity

Question 3

Affinity Chromatography

Answer 3

Used to purify many immunological reagents

Question 4

Monoclonal Ab

Answer 4

A single clone of one B-cell is produced by fusing that cell to a tumor cell and isolating the clone with the Ab specificity of interest
NO HETEROGENEITY
Have low affinity, but no avidity

Question 5

Steps to making a monoclonal Ab

Answer 5

Immunize an animal
Isolate spleen cells from immunized animal
Fuse spleen cells to cancer cells
Select only those that are hybrids
Clone the hybrids
Select clone with specificity that you are interested in

Question 6

Problem with using non human Abs in humans

Answer 6

Have an immune response to non-human Abs

Question 7

Chimeric

Answer 7

Variable regions from mouse

Constant from humans

Question 8

Humanized

Answer 8

Only the points of contact with Ag remain mouse

Question 9

Human monoclonal

Answer 9

Made through molecular biology techniques

Question 10

Immunoassays - ELISA

Answer 10

• Ag stuck to bottome of well
• Ab is added, allowed to incubate, excess Ab washed
• 2nd Ab that has enzyme linked molecule (that binds to 1st Ab) added
• Incubation, and excess 2ndary washed
• 2ndary Ab detected by adding a chemical reagent that turns color in presence on En bound to 2ndary Ab

Question 11

Immunofluorescence

Answer 11

Tissue or cells are reacted with antisera specific for a cell marker or pathogen
Unbound antiserum is removed by washing
A 2nd Ab specific for the 1st Ab is added and allowed to bind
Attached to 2nd Ab is a fluorescent molecule
Cells viewed through microscope

Question 12

Fluorescence Activated Cell Sorter - Flow cytometry

Answer 12

Mixture of cells are labeled with fluorescent Abs

Analyze cells with lasers and sort

Question 13

Western Immunoblot

Answer 13

• Mixture of proteins such as cell lysates or serum are separated electrophoretically
• Separated proteins bound to nitrocellulose paper
• Ab to protein of interest then added, wash unbound, add 2nd Ab
• Ab detected by En-linked 2ndary Ab

Question 14

Possible constant light chain regions

Answer 14

Kappa and lambda

Question 15

Epitope

Answer 15

Part bound by Ab

Question 16

Types of Epitopes

Answer 16

Linear

Discontinuous

Question 17

What is meant by Abs are HETEROGENOUS

Answer 17

Difference in how and where Abs bind to same Ag

Question 18

Polyclonal Abs

Answer 18

Abs made from diff B-cells for same Ag

Question 19

Uses of Abs in Lab

Answer 19

-Abs are used to measure many biological parameters

Question 20

How to make Abs more specific

Answer 20

• Affinity purify
• Absorb non-specific antisera
• Monoclonal Ab

Question 21

Affinity Purify Ab

Answer 21

Make Ab more specific by purifying the Ab you want

• Add Ag with beads
• Add diff Abs
• Wash off Abs not attached to Ag and bead
• Remove bead from Ab
• Left with specific Ab

Question 22

Absorb Cross Reacting Ab

Answer 22

Remove the contaminated Ab

• Pour mixture of Ab into Ag attached to beads (that arent interested in)
• Pull out Abs not attached
• Pulled out purified Ab

Question 23

Serum Sickness

Answer 23

Immune reaction to Ab (usually not our own)

• We are sometimes given Abs (that are foreign) to help, but build up Abs against foreign Ab
• Next time injected will have serum sickness