Basic Colorimetric Proliferation Assays: MTT, WST, and Resazurin.

This chapter describes selected assays for the evaluation of cellular viability and proliferation of cell cultures. The underlying principle of these assays is the measurement of a biochemical marker to evaluate the cell's metabolic activity. The formation of the omnipresent reducing agents NADH and NADPH is used as a marker for metabolic activity in the following assays. Using NADH and NADPH as electron sources, specific dyes are biochemically reduced which results in a color change that can be determined with basic photometrical methods. The assays selected for this chapter include MTT, WST, and resazurin. They are applicable for adherent or suspended cell lines, easy to perform, and comparably economical. Detailed protocols and notes for easier handling and avoiding pitfalls are enclosed to each assay.

Alternating-magnetic-field induced enhancement of diffusivity in Ni-Cr alloys.

For applying an alternating magnetic field (AMF) in materials processing it is of high significance to understand the physical mechanisms behind the change in diffusivity in the AMF. In this work, the effect of the AMF on interdiffusion in a Ni-Cr alloy was investigated with a diffusion couple. The interdiffusion coefficient was found to increase with increasing AMF intensity. The faster diffusivity is a consequence of the enhancement of the dislocation density in the diffusion couples that was confirmed by the broadening of X-ray diffraction peaks. The higher dislocation density is attributed to the magnetoplastic effect (MPE). Theoretical considerations on the relation of MPE, dislocation density and diffusivity are in agreement with the experimental results.