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Sample Preparation

Isolation and Enrichment of Biomolecules

The isolation, extraction, enrichment, or purification of proteins, peptides, phosphoproteins, phosphopeptides, and similar biomolecules are essential sample preparation processes prior to detection and quantification in the areas of metabolomics, lipidomics, proteomics, and biomarker research.
Sigma-Aldrich has commercialized an array of innovative devices and technologies that perform one or more of the following: micro-scale enrichment, sample purification, elimination of contaminants, and desalting.

Select the appropriate product based on the applications indicated below:
Proteins and Peptides: Micro-Purification, Enrichment
Phospholipids: Removal, Isolation
Phosphopeptides, Phosphoproteins: Micro-Purification, Enrichment
Useful Links

Proteins and Peptides: Micro-purification, Enrichment back to top

Supel-Tips C18
C18 packed pipette tips offer exceptional binding and recovery when purifying femtomole to picomole quantities of proteins and peptides. Other benefits include superior sorbent bed stability for cleaner samples.

Pipette Tips

Phospholipids: Removal and Isolation back to top

This technology offers the simplicity of protein precipitation and the selectivity of Solid Phase Extraction (SPE) for the targeted removal of phospholipids and proteins in biological plasma/serum.
Phospholipids are one of the principal causes of ion-suppression in LC-MS; they often remain on the analytical column after sample analysis and elute uncontrollably in a LC run sequence.

HybridSPE Precipitation

Phosphopeptides: Micro-purification, Enrichment back to top

Supel-Tips Zr, Supel-Tips Ti
Zirconia and Titania packed pipette tips are convenient and useful for extraction, enrichment and micro-purification of phosphopeptides and similar bio-molecules through hydrophobic interactions.



PHOS- Select™ Gallium/Silica spin column kit
This column kit is designed to increase the concentration of phosphopeptides from tryptic digests by immobilized metal affinity chromatography (IMAC). The phosphopeptide capture matrix is a novel Ga3+ chelate silica based on a proprietary nitriloacetic acid (NTA) analog. The silica beads are approximately 20 microns in diameter with a pore size of 1,000 Angstroms.
The matrix is packed into spin columns for easy, micro-scale affinity capture of phosphopeptides (see workflow).
Use to purify samples containing up to 25 nmoles of phosphopeptides.

View the workflow highlighting the use of the Ga(III) spin columns for digestion and selective enrichment of phosphopeptides from a tryptic digest sample

PHOS-select™ Gallium spin column

PHOS-Select™ Iron Affinity Gel
This is a novel Iron (III) chelate matrix based on Sigma’s NTA analog chelate ligand. This matrix offers high capacity affinity binding of molecules containing phosphate groups. It allows affinity enrichment of phosphopeptides obtained from protein tryptic digests or direct transfer of phosphocompounds for analysis via HPLC or Mass spectrometry.

PHOS-Select™ High Capacity Iron Coated Plate

High Capacity Iron Coated multiwell plates are prepared with a novel iron [Fe(III)] chelate matrix based on our proprietary NTA analog chelate ligand. This matrix provides high capacity affinity binding of molecules containing phosphate groups.
The high capacity coating allows for a variety of applications:
· Affinity enrichment of phosphopeptides obtained from protein tryptic digests
· Affinity enrichment of phosphoproteins from crude mixtures
· Affinity enrichment of small organic phosphocompounds (e.g. adenosine 5'-monophosphate)
· Direct transfer of phosphocompounds for analysis (HPLC, mass spectrometry)

Capture Media
for Phosphoproteins

Useful Links back to top

Post Translational Analysis

Proteomics Learning Center

Proteomics Applications Center

Proteomics and Protein Expression Product Guide