Detecting molecules

A process for increasing the relative abundance of a molecule having a low relative abundance in a test sample including:

• a) fractionating a test sample including molecules according to a property of the molecules of the test sample, to form at least two fractions of the test sample;
• b) providing a population of hosts for producing a group of antibodies for binding to molecules of the test sample that have a high relative abundance in each fraction of the test sample;
• c) introducing each fraction of the test sample into a host of the population so that each host of the population receives one of the fractions of the test sample, to produce the group of antibodies;
• d) utilising the group of antibodies to deplete molecules from the test sample, to form a first depleted sample having an increased relative abundance of a molecule having a low relative abundance in the test sample.