Fast and efficient separation of larger molecules (proteins, nucleic acids, complex carbohydrates, etc.), from small molecules (nucleotides, buffer salts, etc.). Processes sample volumes of 20–50 μl. Excellent recovery of DNA fragments with sizes greater than 135 base pairs while removing > 98 % of salts, NTP's and other unwanted low-molecular-weight impurities. Proteins, peptides, and protein conjugates > 100 kD are efficiently separated and desalted from unwanted low-molecular-weight impurities. The column gel is hydrated with either reagent-grade water or a suitable buffer, and then spun in a microcentrifuge to remove the intersititial fluid. After your sample is applied, the column is spun again to simultaneously remove impurities and exchange your sample into the buffer of your choice.