On your journey to Biomarker profiling, you will reach the point where you need to quantify the proteins of interest identified along the way (eg. validation of semi-quantitative array results; biomarker discovery with an initial hunch on which pathway is involved).

At this stage, you will have narrowed down the number of targets you want to look at. However, the use of ELISAs is likely to be still too costly, too time consuming, and may require too much sample volume.