| abstract |
Apparatuses, systems, method, reagents, and kits for conducting assays as well as process for their preparation are described. They are particularly well suited for conducting automated analysis in a multi-well plate assay format. A method is provided for focusing an optical sensor to a spaced apart platform comprising the steps of: providing at least a higher, middle and lower patterned surface, wherein the middle patterned surface and the platform are aligned to each other and wherein a first distance between the higher and middle patterned surfaces and a second distance between the middle surface and lower patterned surface are substantially equal; obtaining a first difference in contrast values between the higher and middle patterned surfaces with the optical sensor; obtaining a second difference in contrast values between the middle and lower patterned surfaces with the optical sensor; and comparing the first and second differences in contrast values. |