New proteomics technology applied to plasma work

Researchers at the Joint Proteomics Laboratory (JPSL) at the Ludwig Institute for Cancer Research and the Walter and Eliza Hall Institute of Medical Research are using a new proteomics technology to remove common high-abundance proteins from plasma before analysis.

According to JPSL proteomics facility manager Rob Moritz, six proteins make up a hefty 86 per cent of plasma protein, with another 28 proteins in the next 13 per cent. But in the remaining 1-2 per cent, there are more than 1 million low-abundance proteins.

"Depleting these high-abundance proteins is a major step towards looking at low-abundance proteins that may be indicative of disease," Moritz said.

The JPSL is the first laboratory in Australia to begin using Agilent Technologies' new Multiple Affinity Removal System (MARS) to remove the six high-abundance proteins from the serum samples. The new technology uses a special affinity column that quantitatively removes the proteins via polyclonal antibodies, without depleting the rest of the serum proteins.

The technology is allowing JPSL researchers to examine plasma from colorectal cancer patients in the hope of finding biomarkers that can be used to identify the presence of the disease in a non-invasive diagnostic test. After depletion, the remaining serum proteins are separated using 2D electrophoresis and then analysed by mass spectroscopy.

"It's really made a huge difference to the process," Moritz said.

The project is part of a major NHMRC funded program led by the Ludwig's Prof Richard Simpson -- the Human Colon Cancer Initiative.