Assay Development Services

  • Target Protein Sourcing/Production

    If the target protein is available from the customer or vendor, we will evaluate purity and functional activity before development begins. If it’s not available, our scientists will produce it using the most efficient and cost-effective expression and purification strategy for your target.

  • Assay Optimization with Target Protein

    We will determine the optimal buffer composition, enzyme concentration, and reaction time & optimize detection reagents to produce maximal signal under initial velocity conditions.

  • Assay Validation

    Validation is tailored to your needs and could include:

    • Dose response testing with control inhibitors
    • Determination of kinetic parameters
    • Pilot screens with target libraries
    • Interference screens

Accelerate Drug Discovery with BellBrook Assay Development and Hit-to-Lead Services

Accelerate drug discovery without adding headcount. In today’s lean biotech environment, timelines are tight, and budgets tighter—yet the pressure to move faster never stops.

BellBrook Labs plugs into your workflow with assay development, screening, and hit-to-lead services built for speed, scientific rigor, and clear go/no-go decisions.

Why Choose BellBrook Labs to Accelerate Your Program?

Leveraging BellBrook’s service expertise will save you time and money. Your project is handled by the same BellBrook scientists who developed the Transcreener assay and have optimized it for more than 100 different enzymes, including kinases, ATPases, GTPases, glycosyltransferases, ligases/synthetases, and phosphodiesterases.

Because we understand both assay and drug development technologies, we will tailor our efforts to meet your specific needs. For example, minimizing consumption of limited reagents or enabling simultaneous screening for inhibitors and activators. And we will work fast. If your target enzyme is in good shape, we can typically complete development within two to four weeks.

What you get with BellBrook Labs:

  • Deep enzyme expertise — Kinases, ATPases, GTPases, methyltransferases, helicases, glycosyltransferases, and more.
  • Proven technologies — Transcreener® FP, TR-FRET, FI detection, plus SAH and RNA unwinding assays.
  • Screening-ready — Optimized for 384- and 1536-well formats with strong Z′ factors.
  • Flexible & collaborative — Tailored solutions whether you need full development or assay optimization.
  • Accelerated timelines — Many projects deliver validated assays within 2–4 weeks.

“Some CROs reserve their best teams for high profile customers. If you’re not right there with them you get less experienced teams… BellBrook understands enzyme kinetics, so it made that part of the project so much easier. The larger CRO didn’t seem to have the expertise we needed in this area.”

“The ADP assay is a great choice for measuring activity for any ADP-generating enzyme in both real time and endpoint formats. The universal detection system has been very useful for more challenging targets.”

“Excellent blend of simplicity & good science. Excellent technical support”

“The assay itself has good reproducibility and provides a clear readout on our enzyme activity. The most important piece, however, is the level of attention to our project and rapid turnaround time. The staff at BellBrook Know what they are doing.”

“The Transcreener AMP/GMP Assay is extremely straightforward to use and is very sensitive. In a UV-based enzyme assay I needed 1 µM enzyme to see a decent signal; however using the Transcreener AMP assay I only need 10 nM. Also, BellBrook Labs have been very helpful with the assay development. Their representative has been very willing to quickly help me get my assay up and running.”

“Through the process of developing and validating an assay for HTS applications, I generated a very nice data package of robust high quality data.”

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Our Assay Development Process

  • 1

    Choose Your Target

    Browse our targets. If you don’t see yours, please inquire. We routinely develop assays for new targets and often have experience with that target or a similar one within an enzyme family.

  • 2

    Talk To A Scientist

    Let’s talk science. We’d like to learn more about your target, your goals, and how we can accelerate your program.

  • 3

    We Develop Your Assay

    Using a proven Transcreener® technique, we’ll develop an HTS-ready assay to measure enzymatic activity with high sensitivity and reproducibility. Assays will be performed in a timely manner at our lab in Madison, WI.

  • 4

    Get a Fast, Clear Report & Ongoing Support

    You’ll receive a report including the raw data and results of the experiments. We can keep things as simple or complex as you like and provide protocols ready for HTS and hit-to-lead.

Example Targets
cGAS
ADK
MDA5
DHX9
CD73
JAK1
WRN
DDX17
CD39
JAK3
METTL3
TYK2
ENPP1
EZH2
MLL4
BTK
ENPP3
PKR
PRMT4
NNMT
TBK1
MAPK1
PRMT5
IKK-beta
CD38
MAPK8
RIPK1
Fidgetin
PARG
TREX1
RIPK2
Katanin
SARM1
GALNT2
p97
Spastin
NSP13
GALNT3
KHK
VPS4A
NUDT5
OAS1
DDX1
VPS4B
SRC
POLQ
DDX3
SMARCA2
AMPK
RIG-I
DDX5
SMARCA4
PARP1
PARP2
SIRT1
SIRT2
BLM
PLK1
SIRT3
IRE1a
Example Target Families
Protein Kinases
Lipid Kinases
Carbohydrate Kinases
ATPases
Acetyltransferases
HDACs
GTPases, GAPs, GEFs
Phosphodiesterases
Helicases
Nucleotidases
Ligases/Synthetases
Glycosyltransferases

Learn More About Our Assay Development Services

BellBrook’s assay development services specialize in small molecule modulators for enzyme drug targets. We have over 15 years of experience conducting assay development. Our experts work diligently with a variety of customers in early-stage drug discovery programs.

From target production to assay validation, we provide quality data and reproducible methods designed to accelerate programs.

The dedicated team at BellBrook Labs performs custom assay development for enzyme-based assays using state-of-the-art Transcreener technology.

Need help choosing the right CRO?

Learn More About Choosing a Biochemical Assay Development Provider Interested in our Services? Contact a Scientist!

Example Assay Optimization with Human cGAS

BellBrook scientists performed a detection of purified, full-length human cGAS with the Transcreener cGAMP FP Assay. Linear response is shown from polarization data converted to cGAMP using a standard curve.

Human cGAS Enzyme Titration

Assay Development Services cGAS Titration

Linear Response Curve

cGAS Assay Linear Reponse Curve

Example Inhibitor Screening & Profiling With Human cGAS

BellBrook scientists performed an inhibitor screening & inhibitor potency profiling of cGAS using the Transcreener cGAMP cGAS Assay.

Inhibitor Screening

cGAMP Assay Pilot Screen

Screen of 1600 compounds. cGAS was used at 10 nM, compounds at 10 μM. Z = 0.62, Z’ = 0.7 illustrate a robust screening assay. Hits were determined to be anything outside of three standard deviations from the mean.

Inhibitor Potency Profiling

IC50 of cGAS Inhibitor

Confirmation of a screening hit using the Transcreener cGAMP cGAS Assay in the FP format. Follow-up assays to triage screening hits can be used to selective bonafide inhibitors for advancement into medicinal chemistry/SAR.

Assay Services Case Study

“A biotech team with AI-derived virtual hits needed biochemical confirmation but lacked internal assay capacity. BellBrook partnered with them to validate hits, run dose-response curves, and accelerate their program into hit-to-lead—turning virtual predictions into actionable data.”…

Download the case study to learn how BellBrook Labs developed a solution.

Download "Case Study: Hit-to-Lead"

Technologies & Platforms We Use

  • Transcreener® Assay Platform
    Measures nucleotide detection (ADP, GDP, AMP, cGAMP) via FP, TR-FRET, or FI readouts. Ideal for kinases, GTPases, ATPases, and cyclic dinucleotide enzymes (PDEs).
  • AptaFluor® SAH Assay
    A universal methyltransferase assay that detects SAH directly, eliminating antibody dependency and enabling HTS.
  • Heliscreener™ RNA Helicase Assay
    Quantitative, fluorescence-based unwinding assay for helicase inhibitor discovery.
  • Custom Solutions
    Tailored detection strategies for novel or emerging targets, including cGAS, TREX1, XRN1, and more.

Transcreener® HTS Assay Overview

BellBrook’s Transcreener HTS assay platform is ideally suited for the detailed biochemical and kinetic analyses required for hit-to-lead programs. Transcreener is an extensively validated HTS platform that produces robust FP, TR-FRET, and FI signals for nucleotides produced by enzymes; e.g. ADP for kinases.

It has been used to screen tens of millions of wells over the last 10 years in pharma and biotech labs.

Transcreener Overview for Drug Discovery Services

Because Transcreener assays use direct immunodetection of nucleotides, they provide more reliable results than alternative methods that rely on complicated assay schemes. In addition, the continuous mode capability enables analysis of inhibitor binding kinetics, such as residence time, which is increasingly recognized as an important factor for drug efficacy.

When appropriate, we integrate additional assay methods to meet customer requirements.

Related Posts & Case Studies.

Resources

Find the right resources to help you get to your solution faster.

Link to: Frequently Asked Questions (FAQ’s)
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FAQ

Link to: Technical Manuals
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Protocols

Link to: Publications
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Publications

Link to: Transcreener® Assays – Instrument Compatibility
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Instrument Compatibility

Link to: Application Notes
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Application Notes

Link to: Posters and Presentations
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Posters

Contact Us to Learn More About Assay Development Services

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Frequently Asked Questions

We offer comprehensive services including:

  • Target protein sourcing or production, where we evaluate customer-provided or vendor-sourced proteins and produce them if needed using efficient expression and purification strategies.

  • Assay optimization, including buffer composition, enzyme concentration, reaction time, and detection reagent tuning to maximize signal under initial velocity conditions.

  • Assay validation, such as dose-response assays with control inhibitors, kinetic parameter determination, pilot screening, and interference evaluation.

  • Screening and profiling screen for novel inhibitors and move forward with SAR.
  1. Choose Your Target: Select from examples or inquire about new targets.
  2. Talk to a Scientist: Discuss your target, goals, and timeline.
  3. We’ll Do the Work: Develop an HTS-ready assay using Transcreener technology at our Madison, WI lab.
  4. Report & Support: Deliver raw data, reports, and ready-to-use protocols for HTS or hit-to-lead applications.

We specialize in the Transcreener® platform—a mix-and-read format offering fluorescence polarization (FP), fluorescence intensity (FI), or TR-FRET readouts—for direct detection of nucleotide products like ADP, GDP, cGAMP, and more. We also offer assays for SAH, RNA unwinding, and incorporate other commercially available assays to ensure project success.

Yes. For challenging or novel enzyme targets, free assay development is available if preceded by purchasing a 100K screening kit or submitting a $20K PO for follow-up services. Deliverables include enzyme titration, buffer optimization, Km determination, robustness testing (Z’), and tool compound dose-response analysis—all within ~3–4 weeks.

  • Kinases: ADK, AMPK, BTK, JAK1/3, MAPKs, IKK, etc.

  • ATPases & Helicases: p97, WRN, DDX family, MDA5, RIG-I, etc.

  • GTPases: KRAS variants, HRAS, RhoA/C, Rab2, Rac1, and associated GAPs/GEFs.

  • Methyltransferases: EZH2, PRMTs, METTL3/14, NNMT, etc.

  • cGAS/STING pathway: cGAS, ENPP1/3, TREX1, TBK1, IKK.

  • Nucleotidases & Glycosyltransferases: CD39, CD73, and more.

For free assay development, data is typically delivered 3–4 weeks from the start of the project.
In general (with paid services), if the target is already well-established, projects usually complete within 1–2 weeks.

You’ll receive raw data, a detailed experimental report, and protocols optimized for HTS, hit-to-lead, or SAR applications. Our team remains available for guidance throughout the process. You’ll be in touch with real scientists throughout the project.

  • Scientific depth: Engaged directly with scientists who developed Transcreener technology.

  • Speed: Fast turnaround and next-day delivery for certain orders.

  • Flexibility: Customized solutions and tailored workflows to fit your specific needs.

  • Reputation: Over 20 years of experience and hundreds of enzyme validations.

Basic structured services include target sourcing, optimization, and validation. A free assay development option is available, contingent upon kit purchase or PO. Contact us directly for a quote tailored to your specific needs and project scope. We offer flexible options, including pay per DRC, compound, or FTE.

Absolutely. Our free assay development program is specifically designed for novel or difficult enzyme targets, especially when accompanied by a qualifying purchase. We’ll let you know if we think it’s a fit quickly, saving you time and money.

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BellBrook Labs
1232 Fourier Drive, Suite 115
Madison, Wisconsin 53717 USA
(608) 443-2400

info@bellbrooklabs.com