Quantitative microbiological assays use either of two responses, growth inhibition or growth promotion. Antibiotics and germicides are assayed by growth inhibition, and vitamins and amino acids by growth promotion. Previous automation efforts in these types of assays are critically reviewed. Design considerations are presented for a new automated system which meets all essential requirements of microbiological turbidimetric analysis. Optimum requirements are discussed separately for dilution, incubation, and measurement. The automated system duplicates all essential characteristics of well-known manual procedures. Dilution and measurement are performed separately and simultaneously, and incubation is made independent of both functions so that incubation time can be optimized for each analysis. This arrangement furnishes the flexibility, versatility, and precision so necessary in present-day automated analytical microbiology.
Keyphrases 0 Microbiological assay, automated-theory 0 Design consideration-automated microbiological assay @ Automated analysis, microbiological-theory, design
The increasing use of turbidimetric microbiological analysis has emphasized the need for a precise, versatile, automated system. Such a system should meet the needs of a large variety of users and the stringent requirements of a living biological system. The theory in this field is very complex and sometimes not well understood. Effective utilization of these theoretical considerations in the design of a practical and versatile automated system has required simplification of theory and its reduction to essentials. The present paper summarizes this theory, relates this work to other efforts in the field, and presents the design considerations that led to the construction of an automated system. In the accompanying paper (l), this system is described in detail, and a laboratory evaluation is presented of the systems used for analysis of certain antibiotics and vitamins.