Lead Discovery Services

BioAssay Systems has developed a range of assays for performing lead optimization and characterization. Our lead discovery services include, but are not limited to, ADMET Services, Enzyme Inhibitor Screening, and Phosphorylation Status Screening.

Enzyme Inhibitor Screening. Our enzyme inhibitor screening services are optimized for modern lead discovery. Evaluate test compounds in regards to their activating or inhibitory effects on target enzyme(s) of interest. Our enzyme inhibitor screening services include, but are not limited to, determination of EC50 or IC50 and mode of action for lead compounds.

Kinase Inhibitor Screening BioAssay Systems has developed and validated a variety of proprietory methods for follow-up study and HTS screening of kinase inhibitors. More details.

Arginase Inhibitor Assay Arginase is a drug target for various diseases, such as cancer, hypertension, atherosclerosis, myocardial ischaemia, congestive heart failure, and diabetes mellitus. More details.

PTP1b Inhibitor Assay Protein tyrosine phosphatase 1B (PTP1B) is a key regulator and primary drug target for type 2 diabetes and obesity. It is also involved in liver regeneration, drug-induced liver disease, non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma. More details.

Monoamine Oxidase Inhibitor Assay Monoamine oxidase is involved in removing the neurotransmitters norepinephrine, serotonin and dopamine from the brain. Monoamine oxidase inhibitors (MAOIs) were the first type of antidepressant developed. More details.

Acetylcholinesterase Inhibitor Assay Acetylhydrolase is the primary cholinesterase that catalyzes the breakdown of acetylcholine and other choline esters that function as neurotransmitters. Acetylcholinesterase inhibitor is a drug that inhibits the breakdown of acetylcholine, thus increasing both the level and duration of action of the neurotransmitter acetylcholine. More details.

Aldehyde Dehydrogenase Inhibitor Assay Aldehyde Dehydrogenases (ALDHs) are a family of enzymes crucial to alcohol metabolism, catalyzing the breakdown of acetaldehyde. Elevated levels of ALDHs have also been associated to certain cancer types. Cancer Stem Cells (CSCs) with heightened levels of ALDHs have shown enhanced survival mechanisms leading to resistance to chemotherapy and radiation. More details.

Other Enzymes
  • Acid Phosphatase
  • Aconitase
  • Alkaline Phosphatase
  • Amylase
  • Arginase
  • Aspartate Transaminase
  • Catalase
  • Creatine Kinase
  • Diamine Oxidase
  • Fumarase
  • Glucose Oxidase
  • Glucose-6-Phosphate Dehydrogenase
  • Glutamate Dehydrogenase
  • Glutathione Peroxidase
  • Glutathione Reductase
  • Glutathione S-transferase
  • Glyoxalase
  • Invertase/Sucrase
  • Isocitrate Dehydrogenase
  • Kinase
  • Lactate Dehydrogenase
  • Lipase
  • Malate Dehydrogenase
  • Mannosidase
  • Monoamine Oxidase
  • Myeloperoxidase
  • Neuraminidase
  • Nitric Oxide Synthase
  • Phosphatase
  • Phospholipase D
  • Pyruvate Kinase
  • Sorbitol Dehydrogenase
  • Superoxide Dismutase
  • Urease
  • Xanthine Oxidase
If the enzyme you are interested in is not listed here, please contact us with your enzyme of interest and we will evaluate the project feasibility.

Signal Transduction and Drug Screening. BioAssay Systems' signal transduction and drug screening services are for evaluating changes in cell signaling as a result of exposure to test compounds. The services allow the screening of phosphorylation status modulators in important cell signalling pathways.

Species Reactivity
Analyzing the test compound's reactivity with different cell species.

Species Reactivity Graph

Test Compound Titration
A titration is run on the test compound to determine its effects and whether it activates or inhibits phosphorylation.

Test Compound Titration Graph

Phosphorylation Kinetics
The phosphorylation kinetics for the test compound are measured at a specific dosage.

Phosphorylation Kinetics Graph

IC50 Determination
To determine the IC50, we run a titration on the concentration of the test compound.

IC50 Determination Graph

Examples of Signal Transduction and Drug Screening Services
  • ERK Phosphorylation Status
    The mitogen-activated protein kinase (MAPK/ERK) pathway plays a key role in cell proliferation, differentiation and migration. Stimulation by mitogens eventually leads to phosphorylation of ERK1 (T202/Y204) and ERK2 (T185/Y187). The MAPK/ERK cascade presents many interesting drug targets for the development of cancer therapies. More details.

  • AMPK Phosphorylation Status
    The 5-AMP-activated protein kinase (AMPK) is a key sensor of intracellular energy balance. AMPK is activated in response to an increase in the AMP/ATP ratio, which can be caused by a number of factors such as muscle contraction, starvation, or hypoxia. AMPK is activated by phosphorylation on Thr-172 within the catalytic domain. AMP binding results in a 2 to 5-fold increase in AMPK activity compared to the basal level. More details.

  • NFκB Phosphorylation Status
    Nuclear factor-kappa B (NFκB) is a transcription factor that plays a central role in many physiological processes (e.g. inflammation, tumorigenesis, and apoptosis). NFκB is activated by a wide variety of stimuli, including inflammatory cytokines such as TNF-α. Phosphorylation of p65/RelA at Ser-536 results in decreased nuclear export and enhanced p65/RelA-dependent transcription. More details.

If the phosphorylation status screening you are interested in is not listed here, Please email or call us at 1-510-782-9988 x 2 to discuss your service needs.

Mitochondrial Membrane Potential. We have developed HTS assays and offer a lead discovery service that measures the mitochondrial membrane potential in living mammalian cell cultures and in permeabilized yeast cells. More details.

Please email or call us at 1-510-782-9988 x 2 to discuss your service needs.

Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET). BioAssay System's ADMET services are ideal for early stage drug discovery and specialized for evaluating test compounds as drug candidates. Screen for leads by testing for absorption, distribution, metabolism, excretion, and toxicity.

Absorption and Solubility determination by
Filter Plate Method
Shake Flask Method

Parallel Artificial Membrane Permeability (PAMPA) Assay Services
- Gastrointestinal (GI) Permeability (Inquire)
- Blood Brain Barrier (BBB) Permeability (Inquire)
- Skin Permeability (Inquire)

In Vitro Cell Viability and Cytotoxicity

If the ADMET service you are interested in is not listed, please contact us with your project details and we will evaluate the project feasability.

Select Publications by BioAssay Systems' Scientists
Rommel Mallaria, Elissa Swearingenb, Wei Liu, Arnold Ow, Stephen W. Young and Shu-Gui Huang* (2003) “A Generic High- throughput Screening Assay for Kinases: Protein Kinase A as an Example”. J. Biomol. Screen. 8: 198-204.

Catherine A. Hong, Elissa Swearingen, Rommel Mallari, Xiong Gao, Zhaodan Cao, Anne North, Stephen W. Young and Shu-Gui Huang* (2003) “Development of A High-Throughput Time-Resolved Fluorescence Resonance Energy Transfer Assay for TRAF6 Ubiquitin Polymerization”. Assay and Drug Development Technologies 1: 175-180.

Shu-Gui Huang* (2002) “Development of A High-throughput Screening Assay for Mitochondrial Membrane Potential in Living Cells”. J. Biomol. Screen. 7: 383-389.

Ellyn Farrelly, M. Catherine Amaral, Lisa Marshall and Shu-Gui Huang* (2001) A high-throughput assay for mitochondrial membrane potential in permeabilized yeast cells. Analytical Biochemistry 293(2):269-276.

Tony Smith, John Chan, Donna Oksenberg, Roman Urfer, Dave Wexler, Arnie Ow, Liping Gao, Alanna McAlorum, and Shu-Gui Huang* (2004). A High-Throughput Turbidometric Assay for Screening Inhibitors of Protein Disulfide Isomerase Activity. J. Biomol. Screen. 9(7): 614-620.

David S. Wexler, Liping Gao, Francisco Anderson, Arnold Ow, Laszlo Nadasdi, Alanna McAlorum, Roman Urfer, and Shu-Gui Huang* (2005). "Linking Solubility and Permeability Assays for Maximum Throughput and Reproducibility". J. Biomol. Screen. 10(4): 383-390.

Shu-Gui Huang (2005) "Progress from HTS to HTL: Current Strategies in Drug Lead Discovery" Review article in Trends in Pharmaceutical Research 1: 5-10.

David S. Wexler, Shu-Gui Huang, Roman Urfer (2004). "Replumbing the Pipeline: A small, biopharmaceutical company's strategy for integrating lead optimization and ADMET screening". Current Drug Discovery, May 2004: 35-38.

Songzhu An, Gene Cutler, Jack Jiagang Zhao, Shu-Gui Huang, Hui Tian, Wanbo Li, Lingming Liang, Mike Rich, Amy Bakleh, Juan Du, Jin-Long Chen and Kang Dai (2001) Identification and Characterization of a melanin-concentrating hormone receptor. Proc. Natl. Acad. Sci. 98: 7576-7581.

Shu-Gui Huang, Donna Oksenberg, Roman Urfer (2005). "High-throughput Turbidometric Assay for Screening Inhibitors of Protein Disulfide Isomerase Activity". US 6,977,142.

Customer Testimonials
Edward T. Wei, Chief Scientific Officer, Orinda Pharma, Inc.
"It is a pleasure working together with BioAssay Systems. I brought samples to their Hayward location and received the results in less than 24 hr. The discussion with Robert Z was courteous, open, and with a depth of knowledge. Robert has a PhD from Stanford. Also, Frank Huang, the CEO, had sufficient scientific curiosity to try out our cleanser and provide feedback! This is beyond the call of customer relations. BioAssay Systems is a company with a lot of expertise and a friendly, responsive approach to problem solving. I will enthusiastically continue to work with them to carry out our research."

Anh-Dung Le, CEO DermaTec LLC
"The guys at BioAssay Systems know their science! I had to develop a bioassay for our company and Robert was very quick to respond to keep us up to date. They are knowledgeable and very resourceful. They directed us to one of the bulk suppliers that could give us a really good deal on our active ingredient. They keep very detailed records for our research needs. I would recommend working with BioAssay Systems on your assay development projects!"

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