CellViCAM--Cell viability classification for animal cell cultures using dark field micrographs.

Online monitoring of cell density and cell viability is a challenging but essential task to control and optimize biotechnical processes and is of particular interest for the growing field of animal cell cultures. For this purpose, we introduce an optical approach for automated cell detection and viability classification of suspended mammalian cells. Our proposed system CellViCAM is capable of evaluating dark field micrographs by means of several image processing and supervised machine learning techniques without the use of any dyes or fluorescent labeling. Using a human cell line as the reference culture, an efficient cell detection procedure has been established also enabling a cell density estimation. Furthermore, a comprehensive but reagent-free viability analysis, based on a semi-automatic training data generation, has been developed. By means of an extensive validation dataset we can show that the CellViCAM approach can be considered as an equivalent to staining-based methods and moreover, how it provides a technical platform for a more differentiated cell state classification into living, necrotic, early and late apoptosis.

Bactericidal effect of delmopinol on attached and planktonic Streptococcus sanguinis cells.

The aim of this investigation was to determine the antibacterial effect of varying concentrations of delmopinol-HCl on attached as well as on planktonic Streptooccus sanguinis cells in vitro. In addition, a possible antiadhesive effect on attached micro-organisms was to be investigated. S. sanguinis cells were allowed to attach to glass surfaces. These as well as planktonic cells were exposed to delmopinol-HCI in concentrations ranging from 0.2% to 0.00005% for 2 min. The percentage of vital bacteria was calculated by means of a fluorescence staining method. Total counts of attached bacteria were performed to determine any possible detaching effect by the delmopinol-HCl. The CFU were determined for the planktonic bacteria. Attached as well as planktonic bacteria showed a marked decrease in vitality following exposure to 0.2% delmopinol-HCl. After exposure to 0.05% this was only the case with the attached microorganisms. The total number of attached bacteria was not reduced by the delmopinol treatment. During initial dental biofilm formation, delmopinol-HCl causes a bactericidal effect when applied in concentrations of 0.05% and higher.