I am trying to resuspend my oligo but I still see some film at the bottom of the tube. Does the film contain my oligo that did not resuspend into solution?
The bottom of the plastic tubes that oligonucleotides are shipped in can sometimes appear cloudy. To find out if your oligo has fully dissolved, you can run an OD260 reading on the resuspension to see if the oligo has gone into solution. The oligo has most likely fully dissolved, but if the readings are lower than expected, then try heating the oligo to 65⁰C for 5-10 minutes and then vortexing the oligo for several seconds. Some modifications and sequences will make it more difficult for the oligo to dissolve.