A better way to look for biomarkers

Millipore has announced an innovative sample preparation method for detecting and identifying biomarkers. The technique combines the company’s ultrafiltration (UF) and micro-volume solid phase extraction (SPE) technologies to reduce sample complexity, improve isolation of lower molecular weight proteins and enhance analysis by mass spectrometry (MS). Samples such as serum, plasma and urine are challenging to analyze because of their high salt and lipid content and abundant number of proteins.

As a result, reducing sample complexity is essential. First, UF membrane filters remove high-molecular-weight proteins from the samples. Micro-volume SPE devices are then used to desalt and concentrate the ultrafiltrate and spot the proteins onto a MALDI target for MS analysis. Compared to traditional alcohol precipitation, ion exchange or affinity depletion methods, the new protocol provides fast, reproducible fractionation of 1 to 96 samples simultaneously. The method has been shown to be effective for both single samples (using Amicon Ultra centrifugal filter devices and ZipTip pipette tips), as well as for multiple samples (using multiwell MultiScreen filter plates with Ultracel membrane and ZipPlate micro-SPE plates).