The interactions between proteins and crystal surfaces can range from totally non-specific physical adsorption, of the macromolecule on the surface to the most highly specific complementarity. Among proteins, antibodies are the tool that nature evolved to recognize foreign invaders. Recognition occurs through complementarity of their binding sites with the surface of the invader. Recognition in antibody-antigen interactions was studied using crystals and monolayers of cholesterol and its structural isomers as well as crystals of dinitrobenzene. Sequencing and modeling of specific antibodies show an impressive degree of complementarity between the antibodies and the organized surfaces they recognize. In the cholesterol system, one antibody binds to monolayers of cholesterol and entcholesterol with affinity in the range of 10(-12) M and high stereoselectivity, but no enantioselectivity. We conclude that the low level of chirality exposed at the monolayer surface limits the chiral discrimination.