Physical Biochemistry Instrumentation Facility @ IUB

List of Equipment

*Instrument*	Make	Model	Year Purchased	Location	Major Applications
Fluorometer	Perkin Elmer	LS50B	2001	SI033	Structure, folding, binding thermodynamics and kinetics
Analytical Ultracentrifuge	Beckman Coulter	Optima XL-I	1998	SI033	Self-association (size, shape, and thermodynamics)
Isothermal Titration Calorimeter	Microcal	VP-ITC	2003	SI033	Thermodynamics of binding
Variable Mode Imaging System	Amersham Biosciences	Typhoon 9210	2003	SI033	Quantitation of gels, plates, autoradiograms, etc.
Circular Dichroism Spectrometer	Jasco	J-715	1999	A715	Structure and interactions
UV/Visible Spectrometer	Varian	Cary 100 Bio	2001	SI033	Thermodynamics of folding and kinetic assays, oligonucleotide melting
Dynamic Light Scattering	Malvern	Zetasizer Nano-S	2004	SI033	Particle size distributions, diffusion coefficients, and molecular weight information
Surface Plasmon Resonance	BIACORE	3000	2001	SI033	Kinetics of binding, binding heirarchies, concentration studies
Scintillation Counter	Packard	1600TR	1994	SI033	Quantitation of assays and substrates

Isothermal Titration Calorimeter (Microcal VP-ITC)

Essentially all studies of biomolecular interactions involve measurements of dissociation constants or free energies of association (∆G = RT ln K_d). However, a detailed understanding of the physicochemical basis of the interactions often requires more detailed measurements of the thermodynamic components of the free energy change (the enthalpy change, ∆H, and the entropy change, ∆S) and the dependence of these parameters on perturbing conditions such as temperature (i.e. the heat capacity change ∆C_p). Isothermal titration calorimetry has emerged as a convenient and reliable method for obtaining these parameters in a model-independent way. In a single titration, the method gives ∆G, ∆H, and the stoichiometry allowing ∆S to be readily calculated. Repeated titrations at several temperatures give a robust measurement of ∆C_p (∆C_p = d(∆H)/dT, if ∆C_p is independent of temperature) and possibly also the temperature dependence of ∆C_p (if the data are sufficiently sensitive). The Facility currently houses a newly acquired Microcal VP-ITC instrument with an experimental operating range of 2° - 80° C interfaced with Origin software for data analysis in a convenient automated package.