Isolation of protein factors that associate directly or indirectly with nucleic acids

An oligonucleotide probe comprising at least one group that conforms to general formula I, set out below:

• A-[C]n-X I
• wherein A includes one or more affinity labels tethered to a nucleotide X by a spacer group of n atoms in length, wherein n is between about 90 and about 170 atoms, wherein A comprises a hapten or an immuno-tag;
• and wherein the nucleotide X is selected from a ribonucleotide, a deoxyribonucelotide, a dideoxyribonucleotide and a locked ribonucleotide (LNA).

An oligonucleotide probe that conforms to general formula II, set out below:

• B-[C]n-Y II
• wherein B is a an affinity label that is tethered to oligonucleotide sequence Y via a spacer group comprising a linear chain of n atoms, wherein n is between about 90 and about 170 atoms, the oligonucleotide sequence Y comprising at least 10 nucleotides of which no less than 10% are locked nucleic acid nucleotides (LNA).

An oligonucleotide probe that comprises a group that conforms to general formula III, set out below:

• wherein B and B′ include an affinity label that is the same or different tethered to respective nucleotides Z and W by spacer groups C and C′ of n atoms in length wherein n is between about 90 and about 170 atoms;
• and wherein the nucleotides Z and W are separated by an oligonucleotide chain V of p nucleotides in length, where p is between 0 and 40;
• the nucleotides Z, W and V being the same or different and selected suitably from a ribonucleotide, a deoxyribonucelotide, a dideoxyribonucleotide and a locked ribonucleotide (LNA), and at least one Z and W is a LNA.