The crude extracts were reconstituted using the respective extracting solvents, and then diluted to various concentrations using an ACE assay buffer.
For the kinetic analyses, the production rates of sterol glucosides were plotted vs. the respective substrate concentrations using the SigmaPlot enzyme kinetic module (Systat Software Inc., ver. 12.0, San Jose, CA, USA).
The compounds were then used as single agents or in combination at 0.1 ×, 1 × and 10 × their respective GI50 concentrations using PD0325901 as a representative MEK inhibitor.
Raw fluorescence intensities were interpreted to final concentrations using a five-parametric fitting model of the respective standard dilution series.
Furthermore, because the aggregability of CNTs and the choice of dispersant vary widely among different studies, the range of CNT concentrations used in respective toxicity studies is wide (from 1 ng/mL to 10 μg/mL), making assessment more difficult.
The resulting extracts were reconstituted with their respective solvents to give the desired concentrations used in the study.
The TEF values of individual PCBs multiplied by their respective concentrations can be used to yield TCDD toxic equivalents (TEQs) (van den Berg et al. 1998).
The concentrations used in the in vitro experiment are comparable to the concentrations which are reached locally after subcutaneous injection of one ampoule of the respective preparations.
For the subsequent in vitro studies, the respective HPLC product fraction was used as such and diluted to the required concentration using assay buffer.
Granulocyte monocyte colony-stimulating factor (Leukine, Immunex, Seattle, WA, USA), soluble CD40 ligand (Immunex), and IL-7 (Immunex or R&D System, Minneapolis, MN, USA) were used at the respective concentrations of 100 ng/ml, 200 ng/ml and 10 IU/ml.
