Draw the precipitin arcs form in the immuno-double-diffusion set up below being known that antigen 1 and 2 are totally different, antibody 1 and 2 bind specifically to antigen 1 and 2, respectively. Clearly label the arc with the correspondent pair of antibody-antigen.
Ans: For explaining the picture, let me give a quick introduction. Antigen 1 and antigen 2 are totally different meaning that they have different epitopes that will be identified by specific antibody 1 & 2 respectively. So, following the principle of immunoelectrophoresis when antigen and antibody diffuse towards each other and if they meet in appropriate proportions (equivalence region) they will produce lines of precipitation.