Vydac EVEREST C18 Guard Kit, L 7.5 mm x ID 4.6 mm, 5um - 238GK54EV

EVEREST™ columns contain a new-generation silica-based 300 Å monomeric C18 adsorbent that provides exceptionally high resolution for protein and peptide separations. Their unique selectivity and sensitivity are a result of new bonding technology developed by Vydac that improves C18 surface coverage and deactivates residual silanols.

Previously, the best 300 Å C18 chemistries have had carbon coverage in the 2.8 to 3.6 μmol/m2 range. EVEREST C18 coverage is in excess of 4 μmol/m2 and approximates the theoretical limit based on surface area.

To assess resolution, chromatograms of tryptic digests of several proteins on an EVEREST column and several other commercial 300 Å C18 reversed-phase columns were compared. Peak counts were based on detection by automated chromatography software with parameters set identically for all columns. In the analyses of a tryptic digest of cytochrome c below, specific regions of the chromatogram were examined for the number of peaks resolved. The EVEREST column demonstrated
unique selectivity for both hydrophilic and

• High resolution
• Unique selectivity for both hydrophilic and hydrophobic peptides
• High sensitivity
• Excellent reproducibility
• Long lifetime

High peak countshydrophobic peptides. In chromatograms on the next three pages, total peak count was recorded for tryptic digests injected at high loading with software set to detect even trace-level peaks. Under these conditions, the total number of peptides in the sample is very large and includes peptides from contaminants as well as the primary protein digest. Each peak number was the average of several replicate injections. In each case, the EVEREST column exhibited higher resolution than the other commercial columns, based on total peaks detected.

Other testing has shown that on EVEREST C18 peak shapes for peptides do not change in going from 0.1% TFA to 0.1% formic acid. This is indicative of high carbon coverage and efficient masking of residual silanols. Increased shielding of the base material also leads to increased column lifetimes