Affixing probe to a vertical surface? - (Jul/05/2013 )
Hi, I thought I would post this here even though I am not working with microarray. I want to affix a ssDNA probe to a support but the support would be vertical and not horizontal. For instance, the glass slide is spotted with the probe in microarray and dried there but what if you wanted to coat the inside of a microfuge tube with the probe or coat a glass rod-like probe with the probe? How would you get the probe to stick on the vertical surface when it was wet? Let me know if you have any knowledge about this problem? I would greately appreciate that. FreddieP
IIRC the probes in these sorts of things are held on by electrostatic attraction, not friction, so the orientation shouldn't matter.
The only reason an array has to be made on a flat horizontal surface is because more than one probe is being applied and you don't want the little drops running into one another. Once the DNA is attached, you can hold the array in a vertical configuration not problem.
Now your situation is bit different. It sounds like maybe you want to coat the inside of a tube or a rod all with the same probe (ie an even coating of one ssDNA)? Is that correct? If so no problem. What you need is a surface to which DNA can attach. Microarray substrates typically bind the oligos via electrostatic interaction (long oligos binding to a poly-amine surface) or via covalent attachement (via an amine terminal amine modifier on the olgio onto an aldehyde or epoxy surface).
So - as long as the material you are using can be coated with silane (either an amino-silane or an epoxysilane) you should be good to go. Fill the tube with a solution of your oligo (or put the rod in a tube of oligo solution) incubate for a few minutes and remove the solution and your DNA should be stuck to the surface. Depending on the attachment chemistry you use there may be downstream steps required.
Hope that helps.