if your goal is quantification, you should consider MRM first. If for some reasons you can't use MRM, you can still use spectral counting or extracted ion chromatograms to do quantification. You just need to normalize the sample loading and the instrument performance variation from run to run. mass spec has been around for over 100 years. Quantitation is one of the oldest techniques. MRM is the golden standard of small molecule quantification for long long time.
RE LS 是吗? 王道 >同位素标记的标样. 在以下的两个单位Caltech and Scripps 里边可能只是一条叉道吧? RE LZ: just try Single-cell NEMS-based mass spectrometry or Nanostructure-Initiator Mass Spectrometry (NIMS) 不需要同位素标记omics MS relative papers links:' htp://masspec.scripps.edu/publications/public_pdf/172_greving_2011.pdf and htp://www.lbl.gov/tt/publications/2977pub2.pdf or htp://www.ncbi.nlm.nih.gov/pubmed/19514079 relative PIs web links: http://nano.caltech.edu/people/roukes-m.html and htp://masspec.scripps.edu/personnel/director.php or htp://www.helsinki.fi/cdr/research/group_ketola.htm
l*1
14 楼
RE LS: 同意. 补一篇2010 Nature Reviews Molecular Cell Biology htp://www.nature.com/nrm/journal/v11/n11/full/nrm2973.html full text PDF link: htp://www.imsb.ethz.ch/researchgroup/wbernd/Downloads/proteome_maps its pp6 Fig. 1 noted this MRM proteomics assay technology...
extracted mass for
【在 K******S 的大作中提到】 : if your goal is quantification, you should consider MRM first. If for some : reasons you can't use MRM, you can still use spectral counting or extracted : ion chromatograms to do quantification. You just need to normalize the : sample loading and the instrument performance variation from run to run. mass : spec has been around for over 100 years. Quantitation is one of the oldest : techniques. MRM is the golden standard of small molecule quantification for : long long time.
K*S
15 楼
I think you are HU YOUed and need to read more articles. The whole proteomics field is moving toward MRM. As I was mentioned previously, (follow the money), just check out NCI's CPTC concept. MRM is still the golden standard. The only reasons peptide/protein MRM is lagging behind are techinical issues and the cost to make stable isotope labeled standards. Label free is not sensitive. for something with a change below 50%, you cannot even call it a change because of the variation of the whole technology. If you are looking for big changes, it's working fine though. Same issue for iTRAQ, that's why you see less and less iTRAQ applications.
【在 l**********1 的大作中提到】 : RE LS : 是吗? 王道 : >同位素标记的标样. : 在以下的两个单位Caltech and Scripps 里边可能只是一条叉道吧? : RE LZ: just try : Single-cell NEMS-based mass spectrometry : or Nanostructure-Initiator Mass Spectrometry (NIMS) : 不需要同位素标记omics MS relative papers links:' : htp://masspec.scripps.edu/publications/public_pdf/172_greving_2011.pdf : and
K*S
16 楼
It's funny that you quoted an article from Ruedi Aebersold. Aebersold lab is one the top labs for MRM.
【在 l**********1 的大作中提到】 : RE LS: : 同意. 补一篇2010 Nature Reviews Molecular Cell Biology : htp://www.nature.com/nrm/journal/v11/n11/full/nrm2973.html : full text PDF link: : htp://www.imsb.ethz.ch/researchgroup/wbernd/Downloads/proteome_maps : its pp6 Fig. 1 noted this MRM proteomics assay technology... : : extracted : mass : for
w*s
17 楼
I am curiosu which lab are you from?
【在 K******S 的大作中提到】 : I think you are HU YOUed and need to read more articles. : The whole proteomics field is moving toward MRM. As I was mentioned : previously, (follow the money), just check out NCI's CPTC concept. MRM is : still the golden standard. The only reasons peptide/protein MRM is lagging : behind are techinical issues and the cost to make stable isotope labeled : standards. : Label free is not sensitive. for something with a change below 50%, you : cannot even call it a change because of the variation of the whole : technology. If you are looking for big changes, it's working fine though. : Same issue for iTRAQ, that's why you see less and less iTRAQ applications.
K*S
18 楼
small lab (my ph.d. advisor is fresh AP) but worked a lot of proteomics projects in graduate school and still follow the field.
【在 w****s 的大作中提到】 : I am curiosu which lab are you from?
V*b
19 楼
MRM和MS/MS有嘛区别?
V*b
20 楼
MRM和MS/MS有嘛区别?
l*y
21 楼
But MRM requires you know which protein you want to look at. It may be used for further verification just like everyone used WB nowadays . I don't see why MRM will dominate proteomics field.
【在 K******S 的大作中提到】 : I think you are HU YOUed and need to read more articles. : The whole proteomics field is moving toward MRM. As I was mentioned : previously, (follow the money), just check out NCI's CPTC concept. MRM is : still the golden standard. The only reasons peptide/protein MRM is lagging : behind are techinical issues and the cost to make stable isotope labeled : standards. : Label free is not sensitive. for something with a change below 50%, you : cannot even call it a change because of the variation of the whole : technology. If you are looking for big changes, it's working fine though. : Same issue for iTRAQ, that's why you see less and less iTRAQ applications.
y*x
22 楼
MRM is mutiple reaction monitoring, is arguably most sensitive mass spec analysis to monitor a known target through triple quadropole type mass analizer MS/MS usually means product ion scan, in protein/peptide mass spec, MS/MS spectra were acquired to figure out the amino acid sequence in peptides, that in most cases means to identify proteins in the sample
【在 V***b 的大作中提到】 : MRM和MS/MS有嘛区别?
y*x
23 楼
It might suggest there are more this protein in sample A than in sample B if two samples are parallel prepared
Is this thread about "quantification" ? I didn't say MRM will dominate the proteomics field.
used
【在 l****y 的大作中提到】 : But MRM requires you know which protein you want to look at. It may be used : for further verification just like everyone used WB nowadays . I don't see : why MRM will dominate proteomics field.
MRM is just one type of MS/MS mostly used for quantitation
l*1
27 楼
So what's up next cutting edge MS proteomics method? ZZ Why nanoLiters? Nanoliter Cool Wave® exciting, inexpensive, sample handling platform & technology. Booth 17 Improve sensitivity of MALDI, DART, DESI, SIMS, LDI 10 to 100x LITERALLY! Also, manipulate and spatially, temporally concentrate samples for TLC, MS, IR, NMR, PCR; electrophoresis, fluorescence, crystallization & more. Dispense viscous liquids non-touch (glycerol, blood, serum, ionic liqs., glues) for forensics, defense, medical, pharma, energy, proteomics, iomics, apps. Save expensive labeled stds. Use for blood spot dispensing or DNA sample prep. from PDF book htp://www.asms.org/LinkClick.aspx?fileticket=FHxivrA3CSE%3D&tabid=36 at the 59th ASMS Conference on Mass Spectrometry and Allied Topics Date: 05 Jun - 09 Jun 2011 Place: Denver, Colorado, USA Website: http://www.asms.org htp://www.laboratory-journal.com/event/59th-asms-conference-mass- spectrometry-and-allied-topics papers: htp://www.ncbi.nlm.nih.gov/pubmed/20161086 htp://www.ncbi.nlm.nih.gov/pubmed/18479933 Ps: 60th ASMS Conference on Mass Spectrometry and Allied Topics Vancouver, BC, Canada May 20 - 24, 2012 • Short Courses May 19 and 20 htp://www.asms.org/Conferences/AnnualConference/GeneralInformation/tabid/127 /Default.aspx
【在 K******S 的大作中提到】 : Is this thread about "quantification" ? : I didn't say MRM will dominate the proteomics field. : : used
b*r
28 楼
I agree. Quantitation in mass spectrometry is always a problem. It is easy to generate data, but it is more difficult to get reliable quantitation from the data. MRM is probably the easiest and relatively reliable way for quantitation. But even for MRM, there are also chances of "measuring an ion other than the intended target"; see the discussion on SRM in "Recommendations for mass spectrometry data quality metrics for open access data (corollary to the Amsterdam principles)." Proteomics. 2011 Nov 8. doi: 10.1002/pmic.201100562. [Epub ahead of print] J Proteome Res. 2011 Dec 8. [Epub ahead of print] Mol Cell Proteomics. 2011 Dec;10(12):O111.015446. Epub 2011 Nov 3. Another way is Aqua http://www.sigmaaldrich.com/life-science/proteomics/mass-spectr but it may be expensive and/or not as convenient as MRM.
【在 K******S 的大作中提到】 : I think you are HU YOUed and need to read more articles. : The whole proteomics field is moving toward MRM. As I was mentioned : previously, (follow the money), just check out NCI's CPTC concept. MRM is : still the golden standard. The only reasons peptide/protein MRM is lagging : behind are techinical issues and the cost to make stable isotope labeled : standards. : Label free is not sensitive. for something with a change below 50%, you : cannot even call it a change because of the variation of the whole : technology. If you are looking for big changes, it's working fine though. : Same issue for iTRAQ, that's why you see less and less iTRAQ applications.
b*g
29 楼
for absolute quantitation purpose MRM 里的标样最好也是isotope标记standard,就跟AQUA的出发点一样 所谓的AQUA 在复杂样品中根本就不行,还得上MRM,这样才能降低background 的 inteference
the
【在 b*****r 的大作中提到】 : I agree. : Quantitation in mass spectrometry is always a problem. It is easy to : generate data, but it is more difficult to get reliable quantitation from : the data. : MRM is probably the easiest and relatively reliable way for quantitation. : But even for MRM, there are also chances of "measuring an ion other than the : intended target"; see the discussion on SRM in "Recommendations for mass : spectrometry data quality metrics for open access data (corollary to the : Amsterdam principles)." : Proteomics. 2011 Nov 8. doi: 10.1002/pmic.201100562. [Epub ahead of print]
K*S
30 楼
what the heck is this?
,
【在 l**********1 的大作中提到】 : So what's up next cutting edge MS proteomics method? : ZZ : Why nanoLiters? : Nanoliter Cool Wave® : exciting, inexpensive, sample handling platform & technology. : Booth 17 Improve sensitivity of MALDI, DART, DESI, SIMS, LDI 10 to 100x : LITERALLY! : Also, manipulate and spatially, temporally concentrate samples for TLC, MS, : IR, NMR, PCR; electrophoresis, fluorescence, crystallization & more. : Dispense viscous liquids non-touch (glycerol, blood, serum, ionic liqs.,
b*r
31 楼
你说的很对。
【在 b*******g 的大作中提到】 : for absolute quantitation purpose : MRM 里的标样最好也是isotope标记standard,就跟AQUA的出发点一样 : 所谓的AQUA 在复杂样品中根本就不行,还得上MRM,这样才能降低background 的 : inteference : : the
b*r
32 楼
下面的review paper提到各种定量方法 Current trends in quantitative proteomics. Elliott MH, Smith DS, Parker CE, Borchers C. J Mass Spectrom. 2009 Dec;44(12):1637-60. Review.
RE 单一个分离column进样量从 0.5 ul(500nl) vs 20nl 的质谱 量变就可能成为质变啦, sn线性/回归性上 更何况人家US+瑞士的实验室在开发96/394 分离column 同时进样量2 nl 的 Matrix Nanoliters MS吧? htp://www.imsb.ethz.ch/researchgroup/wbernd Our nanostructure-based mass spectrometry platform, a novel matrix-free surface analysis technology, is being developed for metabolite tissue imaging, activity screening and analyzing nano-arrays. htp://masspec.scripps.edu/personnel/director.php htp://www.scs.illinois.edu/sweedler/publications.html
【在 K******S 的大作中提到】 : what the heck is this? : : ,
l*1
35 楼
Did you or your boss attended below conference? 59th ASMS Conference on Mass Spectrometry and Allied Topics Date: 05 Jun - 09 Jun 2011 Place: Denver, Colorado, USA Website: http://www.asms.org htp://www.laboratory-journal.com/event/59th-asms-conference-mass- spectrometry-and-allied-topics or plan to attend next round:' 60th ASMS Conference on Mass Spectrometry and Allied Topics Vancouver, BC, Canada May 20 - 24, 2012 • Short Courses May 19 and 20 htp://www.asms.org/Conferences/AnnualConference/GeneralInformation/tabid/127/Default.aspx or Pittcon 2012 Course Information Course Title: How To Launch 100% of Liquid Samples Into ESI Mass Spectrometers and More About the Nanoliter Regime Categories: 1 - Liquid Chromatography-Mass Spectrometry 2 - Mass Spectrometry 3 - Proteomics 4 - Sample Preparation htp://www.nanoliter.com/newsevents.htm
【在 K******S 的大作中提到】 : small lab (my ph.d. advisor is fresh AP) but worked a lot of proteomics : projects in graduate school and still follow the field.
【在 l**********1 的大作中提到】 : Did you or your boss attended below conference? : 59th ASMS Conference on Mass Spectrometry and Allied Topics : Date: 05 Jun - 09 Jun 2011 : Place: Denver, Colorado, USA : Website: http://www.asms.org : htp://www.laboratory-journal.com/event/59th-asms-conference-mass- : spectrometry-and-allied-topics : or plan to attend next round:' : 60th ASMS Conference on Mass Spectrometry and Allied Topics : Vancouver, BC, Canada