Stylus™ pipette tips for protein sample preparation.

Now desalt and clean-up a few micro liters of femtomole-level protein in under 30 seconds with The Nest Group Inc.'s Stylus brand pipette tips for sample preparation. Stylus Tips are available in three sizes: 1-10 µL, 5-50 µL and 50-250 µL using D10 (P2) or universal pipette tips containing 1, 5 and 50 µL of polymeric resin, respectively, fixed at their end such that there is < 0.5 µL dead volume.
 

In operation, a Stylus brand ProTip™ is placed on a standard single or multi-channel pipettor. The sample is aspirated and dispensed through the low back pressure polymer to bind and wash the polar molecules or small proteins even in the presence of detergent, buffer salts or polar organic solvents. Elution is in 1 - 4 uL of water. Stylus tips are ideal for preparing samples for Mass Spectroscopy or for other analytical techniques. Unlike other methods, Stylus tips save time by providing a fast, ready-to-use device for off line sample preparation even in the presence of detergents.

The Stylus™ SPTU-001H, 1-10 µL ProTip™ fits a Gilson D10 pipettor.  They have low back pressure and high capacity.  At 90% MeCN they can retain a 1600 MW peptide. At 95% they can retain even smaller polar molecules.

To operate, dilute your sample with 9 parts MeCN and aspirate it into the tip 5-10x to retain the molecules of interest. Blow out the excess liquid. Wash with one volume of 80-90% MeCN by cycling the volume 2x and blow out the excess liquid. Aspirate the required elution volume of water and cycle it 2-3x to elute the peptides.  Some samples require 50 mM formic acid for elution. The need for this must be determined experimentally.