Digital affinity linkage assay

A method of quantifying a target in a sample, the method comprising:

• contacting the sample with a first affinity agent linked to a solid support, a second affinity agent comprising a first label, and a third affinity agent comprising a second label, wherein the first, second and third affinity agents specifically bind to the target, if present, thereby forming a target-labeled affinity agent complex;
• separating the target-labeled affinity agent complex from uncomplexed components in the sample based on the presence or absence of the solid support, thereby generating a separated target-labeled affinity agent complex;
• partitioning at least the separated target-labeled affinity agent complex into a plurality of partitions;
• and
• detecting in the plurality of partitions a number of partitions above the number expected from random distribution that comprise the first and second labels in the same partition, thereby quantifying the target in the sample.