PiStar Kinetic Circular Dichroism Spectrometer

Overview

PiStar is probably our most versatile product and is the first spectrometer system purpose designed for both research grade stopped-flow kinetic and steady-state Circular Dichroism applications. Though primarily optimised for the study of CD kinetics, and in particular monitoring protein folding, a wide variety of absorbance and fluorescence measurements can also be made.

Performance

At the heart of the spectrometer is a high performance double grating monochromator and a high stability xenon light source (or mercury xenon). This is coupled to a light conditioning unit comprising a polariser and photoelastic modulator. The emergent circularly polarised light can then be introduced to the sample handling unit of choice, either the micro-volume cell of the stopped flow drive unit or to a variety of standard cuvette cells in the more conventional equilibrium sample housing. Precise bayonet fittings allow the sample-handling units to be interchanged and aligned in seconds.

The stopped-flow sample handling unit features a low volume interchangeable cell coupled to a rigid and fully anaerobic micro-volume flow circuit. The cell housing can rotate through 90° to permit quick changes of pathlength (2/10mm) without loss of sample or thermosttating fluid. The unit is rigidly docked to achieve a direct coupling between sample and optical bench. With a dead time of just 1ms, rate constants in excess of 1500s -1 can be routinely measured.

The steady-state sample housing unit is a versatile fully thermostattable housing capable of accommodating a range of rectangular or cylindrical sample cuvettes, including flow cells. It is designed to allow a range of equilibrium measurements to be made including titrations and temperature ramps.

Software and Data Acquisition

The PiStar features the new Pro-Data instrument software and electronics systems running on a WindowsTM XP PC.

Versatility

A wide range of accessories are available for PiStar, which can be purchased either at the time of initial purchase, or in the future.

Applied Photophysics is continuously introducing new accessories and enhancing detection modes ensuring our customers remain at the cutting edge of their research.