Which quantity of sample I will need?

For experiment using sample changer, i.e. concentration series (at least 3 concentration necessary), the good value is 100 µL of stock solution. You will than keep 50 µL and dilute the rest by several times. Absolute minimum possible to load is if 10-15 µL in tube (and expose it in static mode), hoping that in the capillary there will be 4-5 µL of liquid to expose. For flow mode at least 20 µL are necessary. The quantity of buffer needed is equal to (n+1)*50 µL, when n is the number of samples with the same buffer, 50 corresponds to an individual load of buffer.

For SEC on line the absolute minimum is 10 µL. Optimal is at least 50 µL. Enough buffer means in L region.

How concentrated samples have to be?

As much you can and sample stays monodisperse. Anything betweeen 5 and 0.5 mg/mL would be good. Lowest measurable concetrations depens on sample size. We have obtained 'reasonable' data with BSA (MW = 66 kDa) of c = 0.02 mg/mL.

What I need to perform SEC/HPLC on line epxeriment?

• your own column(s);
• enough buffer (in L range), good if filtered and outgassed (can be done in sample prep lab just prior to the experiment);
• concentrated sample: minimum 10 µL (better if 50 and more), concentration at least 2mg/mL (better if more);
• some knowledge of a standard SEC experimental set-up and software.

How and when can I reach my Local Contact?

A LC stays on call the day(s) of experiment from 8h to 22h. His/her telephone (local with 4 digits or mobile with 0+) is marked on the white board in the Control Hutch. In addition you can call anytime (24h/24h, 7days/7days) Floor Coordinator 25-25, which can be helpful for example with vacuum troubles or PSS (personal safety system) stuff. He/she can also call the software person on call until 23h. Don't hesitate to call him (and he will contact person on call) if in clearly software troubles mainly during weekends.