UNIT 2.5B Pulsed-Field Gel Electrophoresis

  1. Michael Finney

Published Online: 1 MAY 2001

DOI: 10.1002/0471142727.mb0205bs51

Current Protocols in Molecular Biology

Current Protocols in Molecular Biology

How to Cite

Finney, M. 2001. Pulsed-Field Gel Electrophoresis. Current Protocols in Molecular Biology. 51:II:2.5B:2.5B.1–2.5B.9.

Author Information

  1. MJ Research, Watertown, Massachusetts

Publication History

  1. Published Online: 1 MAY 2001
  2. Published Print: JUL 2000


DNA molecules longer than 25 kb are poorly resolved by standard agarose gel electrophoresis. These longer molecules can be resolved using several techniques that periodically change the direction of the electric field in the gel. This unit describes the simplest and most generally useful of the pulsed-field techniques, field inversion electrophoresis, which can be tuned to resolve molecules from ˜10 to 2000 kb (or more with specialized equipment). To resolve molecules beyond the range of field inversion, it is necessary to use some sort of field-angle alternation electrophoresis such as CHEF (contour-clamped homogeneous electric field; described in an Alternate Protocol). A method is also provided for preparing high-molecular-weight DNA samples and size markers embedded in agarose blocks.