Who know how to use the Gradifrac system? (Amersham) - (Aug/24/2005 )

I am using this system, and I am not very familiar to this system. Anybody can give me some suggestion?

My system comes up with the UV monitor, conductivity monitor and a dual channel recorder.

I would like to know....how can I adjust the scale on the graph paper with the OD measured by the UV monitor? That means, when I have a peak with a certain height, how can I know the OD of that sample?

There are some parameters on the UV monitor allow me to set, i.e. UV range, and on the recorder, mV range. Please teach me if you know about the full scale deflection setting.

A thousand thanks!

I don't know whether yours is the same as ours - not sure what kind of variations are offered. What we have set up is a UV monitor in a black box - it's got a click-dial in the lower right hand side of the box. That sets your max UV range. Whatever it reads, that's what your "100%" mark on the chart paper is (ie, the value "2" means "100% on chart = OD 2.0). I'm fairly confident that your UV monitor will have something similar, whether it be a knob or a series of buttons for setting the sensitivity.

If your baseline fluctuates when you flip this dial, you can adjust it with the small knobs on the chart recorder - this is a fluid-motion knob. Ideally, if you set your OD meter to maximum sensitivity (ie, lowest possible reading) and adjust this knob to zero, you should be all set - decreasing sensitivity should retain your baseline.

As for the conductivity meter, we don't have one. Our second channel measures %B currently being mixed, as estimated by the recorder, so there's a lag time equivalent to the column volume. This is simply adjusted with the small dial on the chart recorder. I'm not familiar with gradifrac-compatible conductivity meters, but there might be a "set 0%" and "set 100%" button on the recorder itself (that's how it is on our FPLC).

Thanks very much for helping me. However, I still have some point that I am not quite sure....I am a newbie.

In my UV monitor, there is two knobs. One for setting the UV range (max 2, min 0.01, and "short"). Another one is the potentialmeter. Do you mean that if I am setting the UV range to "short", I should adjust the chart pen to zero; while when I set the UV range to 2, I should adjust the chart pen to 100%. In this case, I will get 0% as OD 0 and 100% as OD 2. Am I correct?

Another question is that, when I adjust the voltage range on the recorder, the chart scale will be changed also! So, which one should I rely on? How should I calibrate the system? I am getting confused even though I read through the user manual once, twice....Help me...Thanks....