Students' Assignment:-

1.    You are given two solutions, one containing protein X and the other containing antibody to protein X. When you add 1 ml of anti-X to 1 ml of protein X, a precipitate forms. But when you dilute the antibody solution 100-fold and then mix 1 ml of the diluted anti-X with 1 ml of protein X, no precipitate forms.
                    a. Explain why no precipitate formed with the diluted antibody.
                    b. Which species (protein X or anti-X) would likely be present in the supernatant of the antibody-antigen mixture in each case?

2.    What is the difference between double immunodiffusion and  radial immunodiffusion