The overall goal of the instrumented systems for microbiological analysis of body fluids is to perform a complete microbiological analysis on all types of body fluids rapidly, accurately, and at a reasonable cost. Originally, microbiological analytical instruments were designed to measure one parameter and were limited in ranges and restrictions on kinds and conditions of restrictions placed upon the way a sample could be made ready for the instrument. The most desirable instrumented systems will perform all of the functions required for one phase of analysis or ideally the complete microbiological analysis. The instrument system configuration should adequately house the chosen approach to the microbiological analysis and should accommodate a normal day's workload and stay within the weight, power, and size parameters available in the laboratory. Perhaps among the real achievements of instrumented systems is that of focusing the attention of the microbiologists on the precise definition of their analyses, resulting in a better understanding of the microbiological processes.