Immunodiffusion plates, made from PS, are used in radial immunodiffusion to determine the quantity of an antigen by measuring the diameters of circles of precipitin complexes surrounding samples of the antigen that mark the boundary between the antigen and an antibody suspended in a medium.

• Close fitting covers to minimise gel dehydration
• Plate bottoms are recessed 7 mm to prevent scratching on the bench surface
• Hydrophilic plates for easy gel pouring