In vitro diagnostic methods face non-specific interactions increasing their background level and influencing the efficacy and reproducibility. Currently, the most important and employed blocker of non-specific interactions is bovine serum albumin (BSA), an animal product with some disadvantages like its batch-to-batch variability and contamination with RNases.
Amphiphilic water-soluble synthetic copolymers based on the highly biocompatible, non-immunogenic and nontoxic N-2-(hydroxypropyl)methacrylamide (HPMA)-based copolymers or poly(oxazoline)s is highly effective synthetic blockers of non-specific interactions and an effective BSA alternative.
The highest blocking capacity was observed for HPMA-based polymers containing two hydrophobic anchors taking advantage of the combination of two structurally different hydrophobic molecules.