At an initial inspection, MicroGenie appears to have a limited range of procedures designed specifically to analyze proteins; however, many of its procedures can be used with both proteins and nucleic acids. By suitable selection of control parameters, the protein analysis procedures can be made to use a variety of analysis methods that would probably appear as separate menu items in other systems. The homology search and comparison procedures, under the DATA BANK and COMPARE menus, may be used with proteins or nucleic acids, and are covered in more detail in Chapter 19 (MicroGenie: Homology Searches). MicroGenie can calculate the sizes of proteins from their mobility on an electrophoresis gel in relation to known size markers, The MicroGenie manual gives details of this in the Files section, Reverse translation of protein to nucleic acids is discussed in Chapter 17 (MicroGenie: Translation).