GE UV-1 5.Maintenance, 5.1General precautions, 5.2Cleaning the flow cell

5. Maintenance

5.1General precautions

5.2Cleaning the flow cell

5.Maintenance

To ensure trouble free running, users are advised to observe the following precautions:

All liquids passing through the flow cell should be free of suspended particles.

All liquids should be degassed to prevent air bubble formation in the flow cell.

Never allow buffer solutions to dry out in the cell. Always rinse the flow cell thoroughly with distilled water after use.

Handle interference filters with care. Never touch the optical surfaces or expose them to temperatures above 60 °C.

For trouble free operation of the UV-1,it is essential that the flow cell is free of any particulate matter and contaminant films. Ensure that the flow cell is never allowed to dry out without having been thoroughly rinsed. Liquids containing dissolved salts, proteins or other solutes will dry out, leaving contaminants on the inner optical surface of the flow cell.

The cells may be inspected for particles by removing the cell holder and examining the light paths with a magnifying glass.

If the cell contains trapped particles proceed as follows:

1.Remove the cell holder from the optical unit.

2.Connect a syringe to the outlet tubing and squirt a clean solution of ethanol in distilled water (50% v/v) through the cell in small aliquots. Examine the cell from time to time to see when the particles have been washed out.

3.Rinse the cell with particle-free distilled water (about 100 ml) and replace it in the optical unit.

4.Reconnect the cell holder to the system to be monitored.

Most non-particulate contaminants e.g. denaturated proteins, salts etc. can be removed by flushing the cell with the appropriate solvent. Finally, rinse the cell thoroughly with distilled water or clean solvent.

Oily deposits, which increase the tendency to trap bubbles, can be removed by rinsing the flow cell first with a non-polar solvent (e.g. hexane), then with a polar solvent (e.g. isopropanol) and finally with distilled water or with detergent see procedure described on next page.