Concentration to remove a few hundred microlitres of alcohol from a DNA pellet is one of the most simple applications of a Genevac system. In a miVac DNA concentrator this takes approximately 10 minutes, or less. Simply set the temperature, select the method for alcohols or water, and press start. Where a dry sample of DNA is required, concentration to dryness in a centrifugal evaporator is the ideal method, presenting the DNA as a dry film in the tube of plate well.
Proteins and Peptides
Many aspects of the study of proteins require concentration before and after processing. One of the most commonly used techniques at all scales is membrane concentration. The small scale methods used can suffer badly from concentration polarisation a phenomenon observed in membrane concentrations where the protein concentration at the membrane increases due to the removal of liquid. When a protein reaches ultra-high concentration at the membrane interface then gel formation is likely this can reduce the activity of the protein and, if the regime for re-suspension is not effective, lead to loss of yield and activity. One alternative for laboratory scale concentration is to use Centrifugal Vacuum concentration where the solvent is boiled from the supernatant under vacuum so that the temperature of boiling is below the denaturation level of the protein. The most commonly used systems for these applications are the miVac range of biological concentrators or the EZ-2.
Oligonucleotides & Preparation of DNA Microarrays
The manufacture of oligonucleotides commonly has two steps where evaporation is required, evaporation of ammonia solutions following synthesis, and then subsequent evaporation of purified samples. Protection of olignonucleotides from damage during drying is critical, especially where a tag or label has been attached to the DNA.