Students of biology must learn the theoretical basis of molecular biology and also acquire practical experience with the methods used in this critically important and rapidly expanding field. This project will establish an instructional unit in molecular biology in the Introductory Biology Laboratory Curriculum at the University of California at Santa Barbara. This unit is composed of two three-hour laboratory exercises, in which students will explore extraction of DNA from intact cells, restriction endonuclease digestion, the electrophoretic separation of DNA, and analysis of DNA fragment size, and a one-hour computer-assisted restriction mapping exercise.