The present title “Molecular Pathology” has been written for undergraduate, post-graduate students and those engaged in pharmaceutical, pathological, and clinical research. Actually the explosion of new technologies with their vast potential has brought with it the need for clinical researchers to equip themselves and their laboratories with a whole array of new expertise. With the high discriminating power of the DNA systems has come high potential in evidentiary terms, high profile status for many investigations, and not least, a high degree of professional scruting of evidence produced by such technology.