Differential Scanning Calorimetry (DSC) is a biophysics technique that can be used to determine enthalpies associated with various temperature induced transitions. A DSC instrument basically measures the amount of heat required to raise the temperature of the sample (i.e. the heat capacity) over a temperature range. If the sample undergoes a phase transition, the heat capacity of the sample will fluctuate in relation to a reference cell producing a peak in the data. The area of this peak then corresponds to the enthalpy of that transition (ΔH).
Information Available: Enthalpy values (ΔH) for transitions and binding interactions, Gibb’s Free Energy Values (ΔG) and Heat Capacity Values (C).
- Comparison of Protein Stabilities
- Detection of Weak/High Affinity Binding to Proteins
- Determination of Protein Oligomerization
- Thermodynamic Structural Information
Instrument Info: VP-DSC (MicroCal, Installed Jan. 2001)
Short Term Noise (RMS average from 5 °C to 110 °C): 1 µcal/min (0.07 uwatts)
Baseline Repeatability (successive scans from 5 °C to 110 °C): 2.5 µcal/min (0.2 uwatts)
Minimum Response Time: 5 seconds
Operating Temperature Range: -10 to 130 °C
Maximum Scan Rate – Heating: 90 °C/hour
Maximum Scan Rage – Cooling: 60 °C/hour
Scanning Rate: Heating: 0 - 90 °C/hour
Cooling: 0 - 60 °C/hour
Effective Volume: 0.5 ml in a tantalum alloy cell. Stem volume is about 0.085 ml.
Pressurized Chamber: 0 - 30 psi. Can reach to 80 psi with accessory pressure cap.
Signal: Exothermic events will cause the DP signal to deflect in the negative direction. Vice versa for endothermic reactions.
Data Acquisition: 16 bit A/D
Approximately 0.5mL is the total volume of the cell but ~1mL is needed for loading the cell. Additionally, bring 5-10mL of buffer to run blanks and fill the reference cell.
Training involves the completion of one experiment under the supervision of Core Facility personnel. The experiment can be one of the trainee’s choosing.
To get a basic feel for the procedure of the experiment, it is recommended that you review the tutorial before coming in to use the instrument.