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Peak Alignment of LC, GC, MS, NMR data

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Peak alignment procedures for samples from LC-MS and GC-MS (also CE-MS, MS, FT-MS, UV, NMR, MALDI) measurements play an important role during biomarker detection and metabolomic studies in general. As there is always a difference in the samples due to machine drift, samples need accurate correction to point to the same metabolite or component. Several packages have emerged since several years, some of them commercial, some of them free, some of them simple, some of them complex :-).

As the topic is rather complex, there are major pitfalls you may be trapped in. Such problems include: peak finding, peak integration, step/bin size selection, centroided or profile data, adduct removal, noise calculation and normalization of the whole dataset. Another problem with large datasets is the computational time. MultiProcessor and MultiCore (including multithreaded implementations) or even cluster support should be enabled. Why? Read the plea for multithreaded software [The free lunch is over]. You may checkout one of the ideal implementations towards using all computational ressources -> mzmine which supports multi-core and multi-processor and even compute-clusters. Another requirement is the use of open exchange formats like netCDF and MZxml. The days of proprietary data formats are counted and will definitely scare away customers who are willing to pay for new software.

You may recognize after you worked with several alignement programs or scripts, that some of the programs do already a complete statistical evaluation using univariate (ANOVA) and multivariate statistics (PLS, LDA, ICA, PCA). This is very helpful for a quick analysis, however a much deeper investigation may be needed with indepenent statistical packages for a complete biomarker identification process. The ultimate biomarker identification tool of course is a workflow or pipeline software using LC, GC, MS and NMR as input and later transfers the found biomarkers to an attached automated structure elucidation process.




 
Created by kind
Last modified 2008-07-22 06:59 PM
 

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