I have a few samples of RNA that I want to use for RACE PCR. The concentration in the samples is too low (around 30-60ng/microlitre) to make RACE cDNA at the moment but I think I can get a high enough concentration if I pool my samples (I have about 30 microlitres from several RNA extractions) and concentrate them down to about 8 microlitres. I am just wondering what the best method for concentrating the RNA. We have a speed vac in the building, but I think it only runs at ambient temperature at the best so I am a bit worried about degrading the RNA. Ive also considered ethanol precipitation but I'm worried about losing some RNA through that method. Ive had another suggestion that I can leave the sample in a fume hood and just let the water evaporate but that sounds a bit risky also. What is the safest method to concentrate the RNA?