This laboratory manual gives a thorough introduction to modern, cost efficient techniques in Molecular Biology, which can find application in many different fields. It is the result of practical experience, with each protocol having been used extensively in undergraduate courses and workshops or tested in the author's laboratory. Thus, they are also likely to work in inexperienced hands the first time they are performed. Stepbystep protocols and practical notes are provided. The distinguishing feature of this manual compared to others is the detailed explanation of the theoretical mechanisms of each step and the discussion of the importance of the techniques. In addition, each protocol includes an indication of the time and expense involved in its application. This knowledge will enable the users to design their own modifications or to adapt the method to different systems. Dr. Surzycki has been teaching undergraduate courses and leading workshops in introductory Molecular Biology for many years, during which time he has extensively modified and refined the techniques he has described in this manual.