Biochemical testing requires the determination of various parameters and the recognition of the main biological chemical compounds, by the usage of biochemical and molecular devices. The objective of this book is to present various processes and procedures to confine and classify unknown bacteria through the molecular, biochemical differences. This can be done depending upon the characteristic gene sequences. Furthermore, molecular tools involving DNA sequencing and biochemical tools based in enzymatic reactions and proteins reactivity will aid to recognize genetically modified organisms in agriculture, as well as for food preservation and healthcare, and improvement through natural products utilization, vaccination and prophylactic treatments, and drugs testing in medical trials.