You've been given a solution containing 5.00 mg/mLmg/mL mg/mL of anti-actin antibody. You need to incubate this antibody with 40.00 mLmL of actin solution at a 1:6000 dilution.

How many µL of antibody would you add?

"One way to separate a mixture of stem cells and differentiatedcells is to label the cell population with a specific antibody.Let's say stem cells express exactly 100 copies of the membraneantigen X, while all differentiated cells express exactly 10 copiesof X.

To the cell mixture, you add a very large solution of 0.1μMantibody (for X). The K_d (dissociation constant) for theantibody-antigen binding reaction is 1μM (treat antibody as if ithas only one binding site).

1) On average, how many antibody molecules will be bound perstem cell? What about per differentiated cell?

2) Find the standard deviation of the of the number ofantibodies bound per stem cell (assume binomial distribution)

You would like to have an antibody that can distinguish FGF1 when in the presence of FGF2 with a specificity factor of 1000 when both proteins are present at 1 nM.You have

an antibody that binds to both proteins with a KD= 5 nM. You find that you can make mutations in this antibody that decrease the affinity for FGF2 without altering the affinity for FGF1.You are successful in making a mutant antibody that has the desired specificity. What is the affinity of the new mutant antibody for FGF2