Manual / Product Insert

1-D PAGE Cleavable ICAT Reagent Applications Development Kit

Version: Version A
Catalog #
  • MS10012(Discontinued)

Manual / Product Insert

Protocol: 1-D PAGE Cleavable ICAT® Reagent Applications Development Kit for Targeted Protein ID and Quantitation (Monoplex Version): P (English )

Version: 05 Sep 2010
Catalog #
  • 4348367(Discontinued)
  • 4339035-LSG
  • 4339036-LSG
  • 4339038-LSG
  • 4339039-LSG
  • 4339040-LSG

Product Literature

Successful HPLC Operation – A Troubleshooting Guide

Manual / Product Insert

Cleavable ICAT Reagent Kit for Protein Labeling

Version: Version B
Catalog #
  • MS10010(Discontinued)
  • MS10022(Discontinued)

Product Literature

Accela Open Autosampler Hardware Manual Rev.B

Product FAQ

Why does the metal needle insert in the heated ESI probe frequently clog when using Orbitrap Exactive or Q Exactive mass spectrometry instruments?

Answer

Clogging of the H-ESI spray needle is generally caused by the presence of non-volatile components in the injected samples. If the non-volatile components of the samples are not removed during sample preparation, they will be injected onto the column where they will gradually bleed off over time into the detector. They may also be directly introduced by the use of non-volatile buffers in the mobile phase. Non volatile buffers should be avoided in LC-MS analysis because the spray needle will clog frequently and in addition the MS optics will quickly become contaminated.

Clogging issues may be worsened when using a divert valve or bypass valve. This is because when the valve switches to waste the LC flow to the needle is stopped, causing the residual liquid in the hot needle to quickly evaporate. This in turn causes the non-volatile components to deposit on the inner wall of the tubing which will eventually clog it.

When using a divert or bypass valve, the issue may be fully resolved by adding another HPLC pump to supply make-up flow through the needle when the column eluent is bypassed. The second pump is connected to the divert valve or bypass valve so that when the eluent is diverted to waste, clean solvent flows through the needle to help keep it clean. Alternatively, sample preparation procedures should be modified to reduce the amount of non-volatile components in each sample injection.

Answer Id: E16862

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Product FAQ

What are some general quality considerations for drug discovery assays?

Answer

In general, we would recommend considering the following:

Water
- Ultrapure water may be derived from water treatment systems, but the spigot or tubing attached to spigots can become contaminated and in turn can contaminate the water as it is dispensed.
- Please make sure that the membrane/filters are changed.
- Purchase the highest-grade HPLC water.
- Mineral contamination in water:
- The chelates used in TR-FRET assays are very sensitive to Fe3+ contamination. Fe3+ competes with the Tb3+ or Eu3+ for the chelate and leads to a diminished or no assay window.

Plastics
- Sequestering of either the kinase or nuclear receptor, substrate, test compound or any component used in the assay can occur with different sorts of plastics.
- Use the assay plates recommend in the protocol if there is one.
- For TR-FRET Assays, white plates of the same plastic can be substituted for the black plates and they do perform better on some instruments and for assays with small windows.
- White plates cannot be used for fluorescence polarization (FP) experiments.
- Once an assay has been established and is running smoothly, please feel free to compare the results with any assay plate that you use more regularly.

Instrument
- Optimize and test the instrument prior to performing the assay.
- Test the instrument settings using reference fluorophores or standards.
- Include a water blank of the same volume as the assay. Since a “water blank” is non-fluorescent, it provides information on instrument noise, electrical variances or other issues unrelated to the assay reagents.
- Contact the instrument manufacturer to improve optimization. Optimizing the instrument may include adjusting the gain (distance of optics from sample) and the voltage on the photomultiplier tube (PMT; the detector).

Answer Id: E16532

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Product Literature

Application Note: Eliminating Delays Caused by Column Wash and Reconditioning to Increase Throughput for Gradient HPLC/UHPLC Methods

Product Literature

Viper and nanoViper Fingertight Fitting Systems – Tool-Free LC Connections for HPLC, UHPLC and nano LC Systems

Manual / Product Insert

Surveyor MS Pump & Surveyor MS Pump Plus Hardware Manual Rev.D

Version: FEB.2016

Product Literature

Newsletter: Advances in Ion Chromatography

Product Literature

Application Note: Food Safety Applications Notebook: Adulteration

Product Literature

Brochure: Vanquish UHPLC System - How Solvent Delivery Technology Can Improve Confidence in Peak Identification and Quantification