Product News: New High Throughput Screening (HTS) Assay to Aid Researchers in Their Search for Breakthrough Drugs Targeting Epigenetic Pathways

13 Oct 2017

The AptaFluor™ SAH Methyltransferase Assay is an enabling new high throughput screening (HTS) assay to aid researchers in their search for breakthrough drugs targeting epigenetic pathways.

Methyltransferases have become a major focus of drug discovery for cancer and other diseases driven by epigenetic factors.  BellBrook Labs’ new, ultra-sensitive AptaFluor™ SAH Methyltransferase Assay eliminates cost and sensitivity barriers that are slowing the discovery of methyltransferase inhibitors.

Methyltransferases produce a variety of methylated products, but most use S-adenosylmethionine (SAM) as the methyl donor, leaving S-adenosylhomocysteine (SAH) as a common reaction product. BellBrook scientists engineered a naturally occurring SAH aptamer to produce a fluorescent signal on binding to SAH, resulting in a non-radioactive assay with unparalleled sensitivity.

By directly detecting SAH, the new AptaFluor assay is universal and can be used with virtually any methyltransferase enzyme.  The assay utilizes a simple mix-and-read format with a far-red positive TR-FRET readout, ensuring its compatibility with automated dispensing equipment and plate readers commonly used for HTS.


  • LLD of 0.6 nM SAH - Perfect for low turnover methyltransferases
  • Robust assay with Z' values greater than 0.7 under initial velocity conditions
  • Use with SAM concentrations as low as 100 nM
  • Reduces enzyme usage by 30X or more
  • Assay at or below Km for SAM


  • Monitor methyltransferase enzyme activity
  • Characterize and validate potential hits
  • Determine inhibitor potency
  • Profile inhibitor selectivity
  • Mechanism of action studies