Help! SPR in self-complementary DNA

Hi all

We are about to make some SPR experiments in self-complementary DNA sequences by biotinylating the 5' end, but we are afraid it can be problematic to have both 5' sides biotinylated. Any suggestions about what can be done to work out this problem?

Thanks in advance
Luis

Hi,

I would inject free biotin after immobilizing the first biotinylated DNA strand. To make sure this is OK add one channel with only free biotin blocking all the streptavidin channels. That will leave two channels in the Biacore (2000/3000) to do the reverse experiment.

Arnoud

Hi again

Thanks for your help. This would work with separated strands, but we are dealing with duplexes. We think trouble might come if the opposite strand blocks the channel before adding the free biotin.

Cheers
Luis

Hi

>> We think trouble might come if the opposite strand blocks >> the channel before adding the free biotin.

How do you mean? These channels are for to big (high) to block with DNA. Can you be more precise?

Arnoud

In our duplexes, both 5' extremes will be biotinylated, and can be fixed to the surface. We are interested in fixing only one of the 5' ends.
(I am new to this technique and went wrong in my last reply, sorry).

I'am think that won't be possible, or you have to find a method to block only one side of the of the duplex.
I can't think of a method now.