PRACTICAL DNA TECHNOLOGY IN SCHOOL .3. MAPPING AND METHYLATION

Since the introduction of practical work in DNA technology to school s cience courses, there has been a need to expand on the limited set of available protocols to demonstrate further biological principles. The current paper sets out two additional practical exercises which can be used in schools. The first experiment involves restriction analysis o f bacteriophage lambda DNA to map its cos sites, and in the second exp eriment the effect of methylation of lambda DNA on restriction enzyme digestion is examined. Based on practical exercises already widely ava ilable, these protocols extend analysis of actual molecular events and aid in their interpretation (Miller, 1993, 1994; Madden, 1993; Harris on, Sampson, and Harrison, 1992).