RX.2000 Rapid Mixing Stopped-Flow Unit

Measure millisecond reactions by UV-vis absorption spectroscopy

Overview

The RX.2000 is a high performance stopped-flow accessory that enables your existing UV-vis spectrometer, fluorimeter and CD polarimeter to be used to follow reactions that are at least a thousand fold faster than those accessible manually.  With a dead-time of only 8ms, first order reaction rates in excess of 200s^-1 can be followed.

The RX.2000 is easily the most accomplished device of its type, making use of the latest advances in stopped-flow design, combined with the simplicity, robustness and reliability of high quality instrument engineering. In one action the RX.2000 mixes two reactants, fills a sample cell, stops the flow and simultaneously provides an output trigger. Its dual pathlength micro-volume cell employs the latest silica fusion technology to give the highest possible optical efficiency and specification. All crucial sample flow circuit surfaces are biocompatible and chemically inert. In addition, carefully selected materials are used throughout to protect the instrument from aggressive chemicals. In addition the entire flow circuit and the drive syringes themselves are located within a thermostattable bath for accurate sample temperature control.

Key Features and Benefits

• Short Dead Time. The dead time of the RX.2000 is only 8ms, as determined by the protocol of Tonomura et al (Anal. Biochem 84, p370-383, 1978). This enables first order reaction rates over 200s^-1 to be measured.
• Total Thermostatting. Uniquely, the entire flow circuit of the RX.2000 is thermostated (including drive syringes). In addition to providing reliable temperature equilibration, this also has the added benefit of aiding in the rigorous exclusion of oxygen from the entire sample when undertaking anaerobic work.
• Chemical resistant materials. Carefully selected materials are used throughout to protect the instrument from aggressive chemical spillage.
• Wide temperature range. High performance syringes with canted seals are used exclusively, providing reliable operation over a wide temperature range.
• Large ratio mixing capability. The drive syringes can be readily substituted to allow mixing ratios from 1:1 to 1:10.
• Universal compatibility. The RX.2000 can be fitted in seconds without tools to any spectrometer that can accommodate a standard 1cm rectangular cell.
• Exceptional Sample Economy. The prime volume of the RX.2000 is only 260µl per reagent (with the standard umbilical length of 60cm) and the subsequent volume per shot is only 100µl. Other lengths of umbilical can be supplied on request.
• Adjustable Drive Volume. The volume required per determination can be altered by adjusting the position of the stopping block/trigger mechanism. This flexibility is of particular importance when performing large ratio asymmetric mixing experiments, and when eliminating air bubbles from the flow circuit.
• Armoured Umbilical. The 60cm umbilical is armoured to prevent damage. The observation cell can therefore be positioned through tight turns without constricting the flow of the thermostatt fluid.
• Triggering. The RX.2000 is provided with the following popular triggering configurations, TTL, open collector and switch contact. The trigger output is accessed by a standard 5 pin DIN socket.
• Digital Temperature Display. This integral feature, fitted as standard, indicates the sample temperature in the cell to within 0.10°C. It also features programmable high and low temperature alarms.
• Pro-Data Software Support. The RX.2000 rapid mixing stopped-flow is supported by the latest Chirascan Pro-Data software.

Specifications

	Dead Time:	8ms
	Optical Pathlengths:	2mm and 10mm for absorbance/fluorescence/circular dichroism
	Widow Sizes:	30mm2 and 6mm2 for fluorescence detection
	Cell Material:	Spectrosil
	Beam Height:	15mm from base of cuvette (other beam heights supplied on request)
	Min. Vol./Shot/Reagent:	120µl
	Prime Volume:	260µl with standard 60cm umbilical
	Syringe Volume:	2.5ml with canted seals as standard
	Ratio mixing:	Up to 10:1 by using different sized syringes
	Temperature Range:	0 – 60°C. Digital temperature display to 50°C with high and low adjustable alarms
	Triggering:	Anti-bounce, TTL, open-collector and switch-contact
	Flow Circuit:	Biocompatible and chemically inert
	Construction:	Constructed from chemically resistant materials throughout
	Anaerobic Facilities:	An anaerobic accessory (AA.1) is available to facilitate rigorous exclusion of oxygen
	Drive System:	Manually or pneumatically driven (optional accessory DA.1)

A range of accessories is available to further enhance the capabilities of the RX.2000 stopped-flow unit.