Alejandro Martin Cohen

9 Questions 16 Answers 0 Followers

Questions related from Alejandro Martin Cohen

Any 'recommended' reference standard mix for metabolomics analysis using LC-MSMS?

We just acquired a LC-MSMS (QExactive) for targeted and non-targeted (discovery) metabolomics. I'm in the process of method development, and I'm wondering if anyone has a used (and approved!) a...

16 November 2017 6,753 4 View

How to share (export) chromatograms and spectra acquired with Thermo XCalibur?

Hi RG community, I run LC-MS/MS experiments on a Thermo VelosPro Orbitrap, and I often need to share the raw data (chromatograms and spectra) with colleagues. Sometimes, devil is in the detail, so...

28 September 2017 9,457 5 View

Proteomics DB search engine for 'unexpected' modifications?

Hi RG community I'm analyzing some proteomics datasets acquired by LC-MSMS on a VelosPro Orbitrap. I'm wondering if anyone knows of a free program to search the files for unknown/unexpected and...

13 April 2017 9,220 4 View

Any good free software for protein intact MW determination from ESI-MS spectra?

I occasionally analyze intact proteins using ESI-MS on a VelosPro instrument. The intact mass of proteins can be calculated from their isotopically resolved MS spectra using Xtract algorithm...

13 July 2016 5,730 6 View

Trifluoroacetic acid (TFA) or formic acid in solid phase extraction prior to ESI-LC-MS analysis?

Solid phase extraction is a common procedure in proteomics to clean-up/desalt samples prior to ESI-LC-MS analysis. I've used it for years in its many forms (ziptips, stagetips, columns, cartridges...

26 February 2015 5,988 7 View

200 vs 300 nl/min for LC-MS/MS in proteomics workflows?

Hi RG community, I run a Proteomics Core Facility with a few LC-MS/MS systems (Dionex U3000 nano LC system) running at 300nl/min flow rate on 0.1mm ID C18 monolithic columns with NewOjective non...

25 April 2014 859 4 View

Proteomics: nano o microflow LC, what's your pick?

There was the notion a few years/decades ago that nanoflow (200-300nl/min) reverse phase LC-MSMS was most appropriate for MS based proteomics experiments. Recent publications and new...

01 January 1970 1,911 3 View

Does biotin suffer reductive methylation??

I'm running a quantitative proteomics experiment on biotynylated proteins (using BioID approach, followed by streptavidin pulldown). I'm planning to use reductive methylation (formaldehyde and...

01 January 1970 3,021 2 View

Just installed LipidSearch 4.1, but it doesn't have many of the deuterated internal stds. Do you know when the 5.0 version will become available???

Just installed LipidSearch 4.1, but it doesn't have many of the deuterated internal stds. Do you know when the 5.0 version will become available??? Unfortunately we cannot build custom IS in 4.1,...

01 January 1970 8,279 1 View