PhyNexus has developed an automated process to desalt or “clean-up” proteins/peptides using C18 and C4 PhyTip® columns in order to streamline sample preparation for mass spectrometry analysis (up to 96 at a time).  When preforming a reversed phase purification using a manual pipette, back pressure in aspirating solutions can cause an inconvenience to the operator and inconsistencies within results. PhyTip columns perform the clean-up with the consistency, ease, and scalability that go hand-in-hand with automation. With the high capacity and versatility in protein binding, the C18 PhyTip column is the optimal choice in developing a fluid MALDI or LC-MS workflow.

PhyTip columns have increased selectivity for polar and non-polar molecules compared to other columns due to the increased bed size and capacity of the PhyTip pipette tip column.  This larger bed size will push the equilibrium of the capture to increased amount of capture product.   When comparing the capacity of some of the leading C18 tips, the C18 PhyTIp column binds more than double the amount of protein per μL of resin while exhibiting a comparable recovery and range.

Due to a lower hydrophobicity than C18 columns C4 columns provide outstanding sensitivity and high efficiency.  Large pore 300 Å C4 columns have been used to large protein fragments and even intact proteins.   C4 is slightly more polar than C18 due to its shorter length and closer proximity to the polar silica substrate.  Therefore, the selectivity of the C4 resin is increased for smaller and more polar molecules.

The columns bind a wide range of protein and polypeptide sizes.  The absolute binding capacity is high with a low loss of smaller or more polar polypeptides.  The sample is recovered in common mass spectrometry compatible solvents.