Methods Microcalorimetry For www.selleckchem.com/products/gdc-0994.html our microcalorimetric studies we used a Setaram MicroDSC III differential scanning microcalorimeter, Joule effect factory calibrated. Outer thermostatic loop was provided by a Julabo F32-HE device operating in standard mode. 3D sensor protection was provided with Argon purge gas (99.99% SIAD – TP). Setsoft 2000 V 3.05 software was used for data acquisition and primary signal processing. In each experiment, a sample of 600 μL was introduced in a batch cell with

a capacity of 1 mL (with a maximum sample volume of 850 μL). Adriamycin ic50 Bacterial population We performed the microcalorimetric experiments on a strain of Staphylococcus epidermidis ATCC 12228. Culture medium Bacterial cultures were prepared this website in trypticase soy broth (TSB) which is a mixture of Pancreatic digest of casein (17 g), NaCl (5 g), Papaic digest of soybean meal (3 g), K2HPO4 (2.5 g), Glucose (1.8 g) to 1 liter and a pH of 7.3 ± 0.2 at 25°C. The medium was autoclaved before use and microbiologically pure. For bacterial plating, isolation

and random sample checking of sterile conditions we used trypticase soy agar (TSA) which is a solid medium, with the same basic components as TSB. Sample preparation Discrete colonies of Staphylococcus epidermidis grown on TSA culture media were used to prepare TSB cultures. For bacterial growth, the liquid suspensions were kept overnight at 37°C in the acetylcholine JulaboF32-HE thermostat. Subsequent inocula were prepared, with the desired transmittance measured at 600 nm (T600). Depending on the experiment, serial dilutions of the inoculum were performed. The transmittance measurements were made using blank TSB as reference. TSA calibration of transmittance indicated a concentration of ≈5×107 CFU/mL for the T600 = 95% suspension, the most frequently used dilution

within this study. The sample cells and their hermetically o-ring sealing caps were sterilized at 121°C and kept sealed until use. Procedure The sample cells were filled at room temperature and were hermetically silicon o-ring sealed. A batch cell containing 600 μL sterile TSB was used as reference for differential scanning microcalorimetry (μDSC). Two types of experiments to test signal reproducibility and variability were performed: a. Experiments on freshly prepared samples Samples were prepared as described above and introduced in the microcalorimeter immediately after preparation. They were allowed to reach thermal equilibrium at room temperature. The working temperature was reached with maximum heating rate then kept constant for the entire experiment and the signal was recorded. b.