This chapter presents a summary account of various amplification techniques for analysis of biological molecules (species) that use some form of optical detection as the endpoint. The analyte species possibly under consideration include lipids, carbohydrates, proteins, and nucleic acids (and combinations of the same such as glycolipids, glycoproteins, etc.), but this review is restricted to proteins and nucleic acids. Of course, there are many detection strategies for both proteins and nucleic acids, but for the purposes of this review, amplification must be involved. We therefore have limited our discussion to immunoassays and nucleic acid techniques employing amplification.