High Throughput Screening (HTS)

Transcreener™ Biochemical Assay Technology:

Our proprietary Transcreener HTS Platform was developed to move more new targets into HTS more rapidly, and to streamline selectivity profiling within a target family. It relies on homogenous fluorescent immunodetection of nucleotides, including ADP, UDP, AMP and GMP, which are formed by thousands of cellular enzymes. Among these are group transferase families, such as kinases and glycosyltransferases, which catalyze the covalent regulatory reactions that are central to cell signaling. Each Transcreener Assay provides a generic detection method for multiple enzyme families. This means that you can focus on evaluating new therapeutic strategies and optimizing lead molecules rather than on time-consuming assay development for individual targets. The Transcreener platform is unique in this regard; there is no other HTS platform with the potential to eliminate so much costly assay development for so many drug targets. Since introduction of the first Transcreener assays in 2005, the platform has been rapidly validated and adopted by pharmaceutical and biotechnology screening labs around the world.

iuvo™ MicroConduit Array Technology:

BellBrook is commercializing microscale cell culture devices with unique advantages for miniaturization and automation of cellular assays. These MicroConduit Arrays (MCA) rely on liquid displacement from microchannels rather than the cumbersome aspiration and replacement used with open wells, yet they are compatible with existing liquid dispensing equipment. The MCA will also allow reconstruction of cells in complex three-dimensional formats that recapitulate paracrine signaling in the context of native tissue, thus enabling better biology. The iuvo arrays are well suited for a broad range of cellular assays including angiogenesis, immunocytochemistry, co-culture and chemotaxis assays; and growth of tumor, primary and stem cells, as well as cell lines.

More Targets

Introduced in 2005, BellBrook Labs’ Transcreener HTS Assay Platform enables seamless incorporation of hundreds of new drug targets into High Throughput Screening. The Transcreener platform relies on proprietary methods for immunodetection of the nucleotide products of group transfer enzymes, enabling entire families of enzymes to be screened using the same detection reagents. The Transcreener platform is unique because it is the only HTS platform available that eliminates costly assay development for so many drug targets.

Transcreener HTS Assay products provide solutions to significant unmet needs in drug discovery by:

• Eliminating months of delays in moving new targets into HTS, with significant R&D cost savings.
• Accelerating the pursuit of new therapeutic strategies for cancer and other grievous diseases.
  
• Improving the ability to avoid adverse side effects, which cause almost half of all clinical failures.
  
• Improving the ability to develop more selective drugs by standardizing HTS methods and data across entire families of drug targets.

Group transfer reactions, such as phosphorylation and glycosylation, serve as important on/off switches for signaling proteins in diverse disease pathways. The stability and activity of small molecules, including drugs and hormones, is also controlled by group transfer reactions such as glucuronidation, methylation and sulfation. The enzymes that catalyze these reactions are generally assayed by detecting the covalently modified product; e.g. a phosphorylated peptide for kinase reactions. However, because the enzymes within a group transfer family have diverse substrate selectivity, this approach requires development of new detection reagents to move new family members into HTS.

Examples of group transfer enzyme families.

The Transcreener platform instead relies on detection of the product of donor molecule cleavage; e.g., ADP for kinases, Coenzyme A for acetyltransferases, AMP or GMP for phosphodiesterases, etc.  There is only one "donor product" for each type of group transfer reaction, so a single set of Transcreener™ detection reagents can be used for all family members, regardless of the acceptor substrate.

Transcreener HTS assay products are based on competitive fluorescence polarization immunoassays (FPIA) for detection of the donor product. FP is used to study molecular interactions by monitoring changes in the apparent size of fluorescently-labeled or inherently fluorescent molecules. The donor product produced from the group transfer reaction competes with a far red tracer (fluorescently tagged donor product), for binding to an antibody. In this format, the starting polarization is high, and decreases as the reaction proceeds.

Better Biology

Cellular assays provide the ability to measure the effects of a compound on biological activity within the cell, with the aim of providing data that is more predictive of a drug’s safety and efficacy. However, significant challenges and limitations are currently associated with screening compound libraries using cultured cells. Miniaturization is important to conserve limited reagents such as cells and compounds. Exceeding a 96-well plate density, however, requires low volume pipetting systems and is often accompanied by increased well-to-well variability. Moreover heterogenous assays such as immunocytochemistry that require wash steps become problematic at higher well densitities. Microfluidics has the potential to dramatically reduce the cell numbers and reagent volumes per data point. However, high throughput microfluidics approaches have thus far required complex liquid handling systems with complex pressure or centripetal-driven pumping systems and intimidating plumbing.

iuvo microconduit array technology marries the miniaturization and andvanced functionalities of microfluidics with exsiting automated HTS liquid handling instrumentation. The principle behind iuvo is passive pumping, which is based on surface tension physics. Surface tension leads to pressure inside drops. All things equal, the pressure is higher inside smaller drops (~1/r). When two drops are connected by a channel, the pressure difference is equilibrated by flow. The smaller drop flows into the channel replacing the channel contents. This means filling a microchannel is as simple as filling a well.

iuvo allows more accurate replication of human biology in situ and brings new ways of probing and measuring the responses of model cell systems into high throughput screening. These devices miniaturize and automate complex biological assays, even with poorly adherent cells or in 3D matrices.

Features and advantages of iuvo:

• Low volume microchannels (1 μl) allow miniaturization for precious cell samples
• Patented passive pumping process allows control by the placement of liquid droplets
  
• Gentle displacement of fluids without aspiration enables wash steps with even poorly adherent cells
• Tunable cell number : media volume ratios, critical for autocrine and paracrine signaling
  
• 3D cell growth in true biological matrices, which also mediate key signal transduction events
  
• Visualize all cells in the channel using an inverted microscope
  
• Customized arrays add a new level of flexibility and control over assay design
  
• Compatible with existing high throughput liquid handling and detection instrumentation

There are three array configurations being developed for commercial sale in 2008. The iuvo Single Array is designed for high throughput cellular assays requiring wash steps. It is suitable for low cell number (primary cells), angiogenesis assays, 3D assays and immunocytochemistry studies in collagen. The iuvo Dual Array is for assays which require two separate compartments, such as co-culture assays of cells in collagen matrices, 3D assays with a separate compartment for media and reagents, and immunocytochemistry studies in Matrigel™. Last, the iuvo Gradient Array creates a linear static gradient in each channel for chemotaxis studies.

About BellBrook Labs

BellBrook Labs is dedicated to providing the pharmaceutical industry with enabling screening tools to accelerate the discovery of more effective therapies. As a small, R&D-driven company, we identify areas where there is a strong need but a significant technical hurdle, and then we develop a solution. The company is focused on taking creative approaches to new product development and to continually improving the level of service provided to our customers. When you communicate with someone from BellBrook it will be immediately apparent that we share your passion for discovering more effective disease therapies and your respect for the complexity of biology.