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| Tip of the Month:
Using H-ESI for Improved Ionization |
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| When using H-ESI (Heated
Electrospray Ionization), the sheath gas pressure remains
similar to cold-ESI, however the auxilary gas pressure must be
increased substantially according to the LC flow rate. The
heated auxilary gas aids desolvation, thus increasing overall
analyte sensitivity and improving S:N. Typical auxilary gas
operating pressure is between 40-60 arbitrary units. |
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| Proteomics:
Identification and Quantification of iTRAQ™ Labeled
Peptides |
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The
identification and quantification of iTRAQ is typically
performed in the MS/MS scan. This requirement was thought to
make the iTRAQ reagent incompatible with ion traps that upon
MS/MS analysis of large m/z iTRAQ-labeled peptides, would
suffer from the "1/3 Rule" and be unable to effectively
analyze the iTRAQ reporter ions at m/z 114 - 117. However, the
ability of the Finnigan LTQ to perform additional scans beyond
just MS/MS allows for the quantification of iTRAQ reporter
ions in a subsequent scan. |
| Download Full
Article (PDF2666 kB) |
| Metabolism Studies
using DDCNL |
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This recorded webinar
shows that Automated Data Dependent Constant Neutral Loss
(DDCNL) Scan Function is a powerful tool that increases the
selectivity for identification of modifications exhibiting a
characteristic mass shift. This technique can be used for the
analysis of post translational modifications, drug metabolism,
and can also be applied to the analysis of other types of
compound transformations, such as degradation or by-product
analyses. It simplifies the analysis of complex mixtures in
biological matrices, and enables rapid characterization of low
abundance species.
Speakers: Gargi Choudhary, Ph.D.,
Senior Applications Scientist and Diane Cho, Ion Trap
Marketing Manager |
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| View Recording
Now |
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| Mass Spectrometry
Seminars - San Francisco Bay Area |
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| You are invited to attend
a FREE all-day seminar highlighting the latest in Life
Sciences Mass Spectrometry and its applications. Speakers
include leading experts and practitioners. Continental
breakfast and buffet lunch will be provided. |
| Agenda &
Registration |
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| Software: An
Automated Approach to Top-Down Biomarker
Analysis |
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The "Top-down"
approach uses the molecular information derived from the
analysis of intact proteins, individually or in mixtures,
combined with fragmentation data from the intact proteins
(inside the mass spectrometer) without prior enzymatic
digestion. The advantages of top-down proteomics are: the
ability to measure the actual intact protein molecular weight,
preserving both the entire protein sequence and the integrity
of post-translational modifications. Currently, top-down
proteomics is limited to FTICR instruments because of
requirements for high resolving power, mass accuracy and
complementary fragmentation methods. Intact protein and
fragment molecular weights can be searched against a
corresponding database in a manner similar to that of the
bottom up approach in order to provide protein
identification. |
| Download Full
Article (PDF 406 kB) |
| Contribute to
Critical Mass |
|
| Critical Mass is now
accepting contributions from subscribers. If selected for
publication, contributors will receive a Thermo-branded
memento as a token of our appreciation. You are welcome to
send contributions in all areas of Mass Spectrometry. Critical
Mass will accept a wide range of contributions including but
not limited to Your Research Interests in Mass Spectrometry or
using Mass Spectrometry, Tips, New Applications, Interesting
Stories on using Thermo's Mass Spectrometers, etc. Please
click on the link provided below to read the Terms and
Conditions for making contributions. |
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| Read Terms and
Conditions for Making
Contributions |
| Trap
Talk: Finnigan™ LXQ™ - Technology You Can
Trust |
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Thermo Electron
recently introduced the Finnigan LXQ linear ion trap mass
spectrometer. This latest addition to Thermo's award-winning
family of Finnigan ion trap mass spectrometers delivers:
-
Fast cycle time for high-throughput identification
- High
sensitivity for detection of multiple analytes in complex
matrices
- Confident structural identification
-
Patented linear ion trap design enables high-quality MSⁿ characterization
- Routine protein and
peptide analysis |
| Register to
receive the
brochure |
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