Hi Neeraj Sharma,

We generally prefer taking 100 microgram/condition for global proteomic analysis and 800 microgram/condition for PTM-based analysis. Upon analysis on mass spectrometry, whether label-free or label-based quantitation, we load 2 microgram of the pooled sample on column.

Thank you.

Dear Sir. Concerning your issue about the minimum amount of protein required in cell lysate for Mass Spectrometry. All of the macroscale techniques described here involve quantities of sample in the milligram to 100 microgram range, which do not necessitate as much care and

precision as microscale samples, generally defined as samples less than 100 μg. Sample loss in the macroscale is not as pressing, for several reasons. The concentration of the sample is easier to maintain with larger quantities, leading to fewer losses in the processing steps. The overall percentage of lost volumes is lower, because milligram quantities of sample require larger volumes to fully solubilize. Milligram quantities can also be divided more easily while maintaining the majority of protein in the sample, including low-abundance species. Large quantities of protein from complex samples are also generally more diverse in their protein composition I think the following below links and the attached file may help you in your analysis:

https://embnet.vital-it.ch/CoursEMBnet/PROT04/Slides/Prot_sep%26sample_prepMS.pdf

https://www.thermofisher.com/sa/en/home/life-science/protein-biology/protein-biology-learning-center/protein-biology-resource-library/pierce-protein-methods/sample-preparation-mass-spectrometry.html

http://www.spectroscopyonline.com/sample-preparation-guide-mass-spectrometry-based-proteomics

Thanks

Thanks, Isam Eldin Hussein Elgailani