The types of gel most typically used are agarose and polyacrylamide gels.  Each type of gel is well-suited to different types and sizes of the analyte.  Polyacrylamide gels are usually used for proteins and have very high resolving power for small fragments of DNA (5-500 bp).   Agarose gels, on the other hand, have lower resolving power for DNA but have a greater range of separation, and are therefore used for DNA fragments of usually 50–20,000 bp in size, but the resolution of over 6 Mb is possible with pulsed field gel electrophoresis (PFGE). Polyacrylamide gels are run in a vertical configuration while agarose gels are typically run horizontally in a submarine mode.  They also differ in their casting methodology, as agarose sets thermally, while polyacrylamide forms in a chemical polymerization reaction.