immobilization of DNA onto a C1 chip

Hello

I try to immobilize dna (at the 5' end labeled with an amine group) onto a C1 chip, but until now without any success.

During DNA injection, there seems to be some attraction to the surface, but the signal drops back to the baseline once the injection is stopped.

Has anyone experience with this. Which immobilization buffer is recommended?

Thanks in advance, Katrijn

Since C1 sensorchip does not have a dextran matrix, the atrraction to the surface will be minimal (or not). In addition the flat surface as a binding capacity of only 10% of a CM5 sensor chip.
You may want to activate and bind your DNA for a longer period. Standard buffer should be fine.
Why did you choose for the C1?

I want a flat chip, so without dextran layer. That's the reason I choose for C1.

With some buffers, I seem to have attraction to the surface, but nothing gets immobilized.

I eventually circumvented the problem by first immobilizing streptavidin onto a C1 chip and then I coupled biotin labeled DNA to the streptavidin. This works well, however, for future experiments, it should be nice if I was able to directly immobilize NH2 labeled DNA to the C1 chip.

Hi Katrijn,

I think we have done this in the past, but it took some optimizations.

We used standard buffer but added high salt concentrations in the immobilization buffers, if I remember correctly it was + 750 mM NaCl in the HBS buffer
Longer incubation times were indeed necessary, together with a high DNA concentration and reduced flow rates

kind regards,