Trap Cartidges

Michrom offers a variety of trap cartridges, packed with application specific HPLC column packing materials for concentration, desalting, detergent removal and protein removal from samples prior to analysis by HPLC, LC/MS, MALDI-MS, Edman sequencing and/or amino acid analysis. These cartridges can be used individually or in a series to cleanup samples manually or on-line, using an HPLC injector or automatically with an autosampler.

Features

·          Three sizes available: Capillary, Microbore, and Macrobore

·          New ADVANCE in-port trap cartridges

SDS removal

Sodium dodecyl sulfate (SDS) is an anionic detergent that is commonly used during the preparation of peptide and protein samples.  With trace levels of SDS present in the sample, chromatographic resolution and reproducibility are compromised and Reversed Phase Chromatography (RPC) columns quickly become contaminated.  Trace levels of SDS bound to peptides and proteins also make mass spectral interpretation more difficult.  Excess SDS can interfere with the ionization of the peptide and/or protein.  The Michrom SDS Trap Cartridge will remove SDS at concentrations up to 1%.  Higher concentrations of SDS form micelles and trap the analytes along with the SDS micelle complex (these samples must be diluted below 1% prior to analysis).  The SDS trap comes in two sizes:  Micro and Macro.  The Micro trap cartridge (1 x 10mm) removes up to 0.1mg of SDS (10ul of 1% SDS).  The Macro trap cartridge (3 x 10mm) removes up to 1.0mg of SDS (100ul of 1% SDS). 

SDS removal is accomplished through a combination of anion-exchange and hydrophilic interaction. The Michrom SDS Trap Cartridges contain a strong anion exchange material for retention of SDS, while peptides and/or proteins proceed to the RPC column (the SDS trap cartridge is plumbed in place of the sample load loop).  Using the usual trifluoroacetic acid (TFA)-containing mobile phases, peptides and/or proteins are eluted with a gradient of organic solvent.  It is extremely important that the pH is 2-4 when working with proteins to allow the protein to become neutral and/or positive so that it does not stick to the SDS trap.  When the organic level exceeds 70%, at least 95% of the SDS desorbs and is eluted to waste.  The column can then be re-equilibrated for the next sample. 

Non-ionic detergent removal

Non-ionic detergents (NID) such as Triton X-100 and Tween-80 are commonly used to help solubilize hydrophobic proteins.  These detergents can interfere with both the chromatography and mass spectral interpretation for samples analyzed by LC/MS. The Michrom NID Removal Trap Cartridge can be used in tandem with a Michrom Protein Trap to remove non-ionic detergents in up to 200ug of protein.  The NID Removal Trap comes in two sizes: Micro and Macro.  The capacity of the Micro trap cartridge (1 x 10mm) is 20ug .  The capacity of the Macro trap cartridge (3 x 10mm) is 200ug.

The Michrom NID Removal Trap contains a mixed-bed ion exchange material that will attract proteins (and some peptides), and allow the non-ionic detergent to pass through to waste.  A multi-step procedure has been developed using a 6 or 10-port injector (Refer to Trap Guide) to combine the mixed-bed ion-exchange cartridge (NID Removal Trap Cartridge) with a Concentration and De-salting Trap Cartridge (Protein or Peptide) for removal of NID.  Sample is applied (port 1) to the NID Removal cartridge while the valve is in the inject position.  Proteins (or peptides) are retained on the trap when loaded using 10% ACN/10mM Buffer*, pH 7.0 (or some other pH not corresponding to pI). The neutral detergent is flushed to waste.  An additional 100uL of the solvent is used to flush residual detergent to waste.  The valve is then switched to load which brings the  Protein trap in-line with the NID Removal Trap Cartridge.  The proteins can then be removed from the NID Removal Trap Cartridge and loaded onto the Protein trap by flushing the traps with 10% ACN/ 0.5M  NaCl.  Salts can then be flushed to waste by washing the traps with 10% ACN/ 0.1% TFA.  The valve is then switched back to inject to allow the proteins to elute from the protein trap with the gradient running through the trap and directly to the RPC column.

The traps will need to be re-equilibrated between injections.  Re-equilibrate the NID trap by flushing  the trap with the buffer solution.  Re-equilibrate the Concentration & Desalting Trap with the low organic solvent conditions that are used at the beginning of the gradient.

Trap Cartidges

Michrom offers a variety of trap cartridges, packed with application specific HPLC column packing materials for concentration, desalting, detergent removal and protein removal from samples prior to analysis by HPLC, LC/MS, MALDI-MS, Edman sequencing and/or amino acid analysis. These cartridges can be used individually or in a series to cleanup samples manually or on-line, using an HPLC injector or automatically with an autosampler.

Features

·          Three sizes available: Capillary, Microbore, and Macrobore

·          New ADVANCE in-port trap cartridges

SDS removal

Sodium dodecyl sulfate (SDS) is an anionic detergent that is commonly used during the preparation of peptide and protein samples.  With trace levels of SDS present in the sample, chromatographic resolution and reproducibility are compromised and Reversed Phase Chromatography (RPC) columns quickly become contaminated.  Trace levels of SDS bound to peptides and proteins also make mass spectral interpretation more difficult.  Excess SDS can interfere with the ionization of the peptide and/or protein.  The Michrom SDS Trap Cartridge will remove SDS at concentrations up to 1%.  Higher concentrations of SDS form micelles and trap the analytes along with the SDS micelle complex (these samples must be diluted below 1% prior to analysis).  The SDS trap comes in two sizes:  Micro and Macro.  The Micro trap cartridge (1 x 10mm) removes up to 0.1mg of SDS (10ul of 1% SDS).  The Macro trap cartridge (3 x 10mm) removes up to 1.0mg of SDS (100ul of 1% SDS). 

SDS removal is accomplished through a combination of anion-exchange and hydrophilic interaction. The Michrom SDS Trap Cartridges contain a strong anion exchange material for retention of SDS, while peptides and/or proteins proceed to the RPC column (the SDS trap cartridge is plumbed in place of the sample load loop).  Using the usual trifluoroacetic acid (TFA)-containing mobile phases, peptides and/or proteins are eluted with a gradient of organic solvent.  It is extremely important that the pH is 2-4 when working with proteins to allow the protein to become neutral and/or positive so that it does not stick to the SDS trap.  When the organic level exceeds 70%, at least 95% of the SDS desorbs and is eluted to waste.  The column can then be re-equilibrated for the next sample. 

Non-ionic detergent removal

Non-ionic detergents (NID) such as Triton X-100 and Tween-80 are commonly used to help solubilize hydrophobic proteins.  These detergents can interfere with both the chromatography and mass spectral interpretation for samples analyzed by LC/MS. The Michrom NID Removal Trap Cartridge can be used in tandem with a Michrom Protein Trap to remove non-ionic detergents in up to 200ug of protein.  The NID Removal Trap comes in two sizes: Micro and Macro.  The capacity of the Micro trap cartridge (1 x 10mm) is 20ug .  The capacity of the Macro trap cartridge (3 x 10mm) is 200ug.

The Michrom NID Removal Trap contains a mixed-bed ion exchange material that will attract proteins (and some peptides), and allow the non-ionic detergent to pass through to waste.  A multi-step procedure has been developed using a 6 or 10-port injector (Refer to Trap Guide) to combine the mixed-bed ion-exchange cartridge (NID Removal Trap Cartridge) with a Concentration and De-salting Trap Cartridge (Protein or Peptide) for removal of NID.  Sample is applied (port 1) to the NID Removal cartridge while the valve is in the inject position.  Proteins (or peptides) are retained on the trap when loaded using 10% ACN/10mM Buffer*, pH 7.0 (or some other pH not corresponding to pI). The neutral detergent is flushed to waste.  An additional 100uL of the solvent is used to flush residual detergent to waste.  The valve is then switched to load which brings the  Protein trap in-line with the NID Removal Trap Cartridge.  The proteins can then be removed from the NID Removal Trap Cartridge and loaded onto the Protein trap by flushing the traps with 10% ACN/ 0.5M  NaCl.  Salts can then be flushed to waste by washing the traps with 10% ACN/ 0.1% TFA.  The valve is then switched back to inject to allow the proteins to elute from the protein trap with the gradient running through the trap and directly to the RPC column.

The traps will need to be re-equilibrated between injections.  Re-equilibrate the NID trap by flushing  the trap with the buffer solution.  Re-equilibrate the Concentration & Desalting Trap with the low organic solvent conditions that are used at the beginning of the gradient.