Strong Cation Exchange (SCX) precolumn fractionation coupled
directly to RPC-MS-MS simplifies complex protein digest characterization for increased
productivity. Whether Multidimensional Chromatographic Analysis of Proteins
(MUDCAP), Signature Peptides, the DALPC method
(Direct Analysis of Large Protein Complexes), ICAT™ (isotope-coded affinity tagged)
labeled, or specific amino acid containing peptides are desired from digested proteins
for proteomic characterization,
this SCX column in tandem with a capillary RPC column allows true
2-D chromatographic fractionation of 1,500-2000
peptides per run at 5 orders of magnitude better detectability than 2-D gel electrophoresis.
Using decreasing pH gradients in volatile buffers for weak
cation exchange of proteins for direct LC-MS analysis. (pdf)
Monoclonal
antibody analysis by weak cation exchange (WCX) (pdf)
Protein
Variant analysis of HgH by WCX illustrates the ability of the PolyCAT
A chemistry to separate deamidation and dehydration products in proteins.
(pdf)
Effect of organic
solvent on WCX of proteins illustrates the value of reducing the hydrophobic
mechanism in ion exchange (pdf)
Strong cation exchange (SCX) of Peptides General
Protocol (pdf)
Detergent
removal from RPC tryptic maps or from proteins using these SDS Removal
guard cartridges coupled to RPC columns in 1.0, 2.1, 4.6, or 10 mmID formats
is easy. Recommended when mapping proteins eluted from SDS electrophoresis
gels to get reproducible tryptic maps. Allows hundreds of runs. Alternatively,
the HILIC technique (see references above) works by removing dyes and detergent
prior to elution of peptides followed by glycopeptides in increasing polarity
and with proteins as large as 100kD. For off line sample prep, use HILIC
micro-SPE tips for detergent or salt removal for LC-MS samples (pdf)
(ALKYL)
Aspartamide™ HIC Chemistries Peptidic bonded phase on silica support
for hydrophobic interaction (HIC) of enzymes, antibodies, or weak RPC of
membrane proteins. Unique silica based, wide pore family of chemistries
with hydrophobic differences maximized to
increase resolution.
Three chemistries, propyl-, ethyl- and methyl- for a 5 fold range of hydrophobicity
40
fold increase in HPLC detector sensitivity Vydac™ 0.32mm, 1.0mm (glass
lined) and 2.1mm ID reverse phase (RPC) columns increase sensitivity 40-,
10-, or 5 fold, respectively, over 4.6mm ID columns. Ideal for LC-MS direct
interface especially the
Low
TFA Vydac MS columns. Use with stream splitter for
simultaneous post column reaction and isolation. Many other chemistries
are available including the HAISIL™Targa®
(low organic, wettable RPC) & Clipeus™ (WOW! selectivity)
C8, C18, CN and Phenyl phases for peptide separations without TFA for better
LC-MS detection.
Vydac, the RPC chemistry
most widely used for reverse phase separations of proteins and peptides,
now has a monomeric
C18 , 238TP chemistry to enhance peptide-silica
interactions. Vydac 238TP comes in 5µm, 10µm, 10-15µm,
15-20µm, or 20-30µm particle sizes, and is available in narrowbore
to prep-scale sizes, as 300Å pore, bonded silica materials.
Bioprocess
monitoring or fast QC methods on Non porous packings 1-3 minute assays
typical with RPC, HIC, or IEX HYDROCELL™ NP-10, and Jordi-Gelô NPR
chemistries. Avoid perfusive band broadening and non porous packings give
high speed (short assays) at low flow rates, making them ideal for rapid
screening or QC assays