It is a truism of science that the more fundamental the subject, the
more universally applicable it is. Neverthelens, it is important to
strike a level of "fundamentalness" appropriate to the task in hand. For
example, an in-depth study of the mechanics of motor cars would tell one
nothing about the dynamics of traffic. Traffic exists on a different
"level" - it is dependent upon the existence of motor vehicles but the
physics and mathematics of traffic can be adequately addressed by
considering motor vehicles as mobile "blobs", with no consideration of
how they become mobile. To start a discourse on traffic with a
consideration of the mechanics of motor vehicles would thus be
inappropropriate. In writing this volume, I have wrestled with the
question of the appropriate level at which to address the physics
underlying many of the techniques used in protein isolation. I have
tried to strike a level as would be used by a mechanic (with perhaps a
slight leaning towards an engineer) - i.e. a practical level, offering
appropriate insight but with minimal mathematics. Some people involved
in biochemical research have a minimal grounding in chemistry and
physics and so I have tried to keep it as simple as possible.