A method for preparing a rubbed substrate structure suitable for use in a liquid crystal assay device, includes reacting a biochemical blocking compound that includes at least one reactive group with an activated modified surface of a support, the activated modified surface of the support having at least one functional group capable of reacting with the reactive group of the biochemical blocking compound, wherein a covalent bond is formed between the biochemical blocking compound and the support producing a support with a surface comprising the biochemical blocking compound. The method also includes rubbing the surface having the biochemical blocking compound to produce a rubbed surface that possesses features that drive uniform anchoring of liquid crystals when the liquid crystals contact the rubbed surface.