ABSTRACT
This chapter presents some of the principal methods used to study the molecular components of cells, particularly proteins, deoxyribonucleic acid (DNA), and Ribonucleic acid (RNA). It describes several approaches to determining a gene's function, starting from a DNA sequence or an organism with an interesting pheno- type. New methods for analyzing proteins, DNA, and RNA are fueling an information explosion and allowing scientists to study cells and their macromolecules in previously unimagined ways. The challenge of isolating a single type of protein from the thousands of other proteins present in a cell is a formidable one, but must be overcome in order to study protein function in vitro. Proteins are most often fractionated by column chromatography, in which a mixture of proteins in solution is passed through a column containing a porous solid matrix. Metal affinity chromatography can thereby be used to purify the modified protein from a complex molecular mixture.
