1. Antimicrobial testing

Tests for assessing the effect and quantities of antimicrobials are commonly used in pharmaceutical and clinical microbiology.

A wide array of tests is needed when developing new antimicrobial agents e.g. to achieve a more rapid effect and to minimize toxicity to the host. A large number of rapid and sensitive testsare also needed to quantify the amount of antibiotics in raw materials and in various steps of production also in serum and urine, especially during pharmacokinetic evaluation. A general assumption is that if it is possible to obtain serum levels of an antibiotic exceeding four-to eightfold the in vitro minimal inhibitory concentration (MIC), this will result in adequate concentration of the drugs at the site of infection.

Another important range of tests are those performed when developing and testing new preservatives and disinfectants.

2. Conventional methods - time and reagent consuming

In addition to plate count techniques, turbidometric methods are widely used in antimicrobial testing. Traditionally turbidometric tests are performed in test tubes and as end point measurements (Ericsson and Sherris, 1971).

3. Bioscreen analyzer system - automation and kinetic measurement under aseptic conditions

Bioscreen offers not only automation of turbidometric methods, but also kinetic measurement under aseptic conditions, thus allowing the use of the whole growth curve for calculating the results. Computer analysis of the growth curve speeds up the calculation and reporting of the results. When developing new antibiotics or preservatives or disinfectants, the kinetic measurement makes it possible to characterize the biological effect i.e. bacteriocidic, bacteriostatic, and the microbial toxicity.