Posted by Kasra
When designing experiments in the lab, we usually say we cannot check for everything. Well, what if we could?! Meissner et al. used only 150,000 macrophages per sample to analyze their secretome. They have been able to detect and quantify protein abundances at the picogram level in a label-free system. Picogram detection limit means that cytokines are readily quantifiable, and Meisner et al. claim it matches with the detection limit of ELISA. I could imagine that in not so long this technology can become more readily accessible, allowing researchers to acquire more pertinent data per sample. We can know the statuses of a multitude of proteins (from cytokines to nonconventionally secreted proteins) simultaneously, not through multiple ELISAs and western blots, and therefore draw much more sensible conclusions from experiments. It will actually be more affordable than separate quantification of each protein, not mentioning dramatically time-saving.
Also, this data can be integrated with other high throughput quantitative analyses of the cell. For instance, Meissner et al. have compared the changes in protein abundance in the secretome to changes in their transcript levels, and roles of different adaptor molecules (in this case MyD88 versus TRIF) and tried to explain how they all relate.
Meissner F, Scheltema RA, Mollenkopf HJ, & Mann M (2013). Direct proteomic quantification of the secretome of activated immune cells. Science (New York, N.Y.), 340 (6131), 475-8 PMID: 23620052