Offline Equipment

Science Group: Soft Condensed Matter Group
Comments:

A commercial stopped flow apparatus (Bio-Logic, Paris, France), especially designed for Synchrotron Radiation SAXS investigations of conformation changes of proteins, nucleic acids and macromolecules, is available.

The instrument consists of a 4 syringe cell with 3 mixer modules manufactured by Bio-Logic. Each syringe is driven independently from the others by an individual stepping-motor, which allows a high versatility of the mixing sequence (flow-rate, flow duration, sequential mixing). For example, injection sequences can use one or up to 4 syringes, and include unequal filling of syringes, variable mixing ratio, reaction intermediate ageing in three- or four-syringe mode, et cetera. The solution flow can be entirely software-controlled via stepping motors, and can stop in a fraction of a millisecond.

The software allows the set-up of the shot volumes of each of the 4 syringes in a certain time interval. Up to 20 mixing protocols can be programmed and macros for the repeated execution of individual frames can be defined. Furthermore, the input and output trigger accessible for user operation can be programmed. In the usual operation modus the start of rapid mixing sequence is triggered from our X-ray data-acquisition system (input trigger).

After the liquids have been rapidly mixed, they are filled within a few ms into a 1 mm quartz capillary - situated in the X-ray beam- , which is thermostatically controlled with a water bath. Depending on the diffraction power of the sample, time resolutions of up to 10 ms can be obtained. The main parameters of the system are:

• Thermostatic quartz capillary (1 mm)
• Temperature stability 0.1°C
• Total sample used per mixing cycle (shot volume): 100 µl
• Maximum 2theta angle of 45°
• Total Volume 8 ml
• Dead volume 550 µl
• Speed: 0.045 - 6 ml/s
• Duration of flow 1 ms to 9999 ms/Phase
• Dead time: 1 ms
• Reservoir volume: 10 ml each

Booking

Non Proprietary Use

• Use as part of approved beamtime: see your local contact
• Not part of approved beamtime: contact laboratory coordinator

Proprietary Use

• Contact the Industrial Liaison Office