Talevi Consulting - blood-based biomarkers (liquid biopsy)


Our Experience



Victor Levenson, MD, PhD, Principal

Dr. Victor Levenson has more than 20 years of experience directing research and development for genetic and epigenetic discovery, with a strong focus on diagnostics and prediction of response to treatment.

Dr. Levenson received his MD and then PhD in Molecular and Cellular Biology. He held faculty positions at the University of Illinois at Chicago, Northwestern University, and Rush University Medical Center.

 Dr. Levenson was the Principal Investigator on multiple grants, published more than three dozen peer-reviewed articles, reviews, and book chapters, and gave numerous invited presentations at different scientific meetings. He is the author of five issued patents and three ongoing patent applications,  in the field of blood-based biomarkers or liquid biopsies.

Our Approach


Our service includes a comprehensive consult to help identify gaps and opportunities, a complete report that includes a project plan with timelines and milestones, a cost analysis, and a schedule. 

We can also contract with you for biomarker development using our proprietary technology (M-TEST) for genome-wide discovery of abnormal methylation in cell-free DNA (liquid biopsy).


We look for informative features in tissues and in cell-free DNA from blood or other biological fluids, combine these features into a composite biomarker using a dedicated software algorithm. We then compute sensitivity and specificity of this biomarker and validate its performance.

Developed biomarker is the final product of our discovery, development, and validation services for blood-based biomarkers. We will help you get there quickly and smoothly. That’s how we ensure your success.

Why Us?


 informative features combined into a composite biomarker provide the comprehensive info required for precise diagnosis, prediction of response, or to determine the natural course of the disease. When several features agree, the biomarker strategies provide multiple layers of confirmation for the right diagnosis or prediction of response. 

Disease and its response to treatment are defined by gene expression, so the best biomarkers in medicine are those that reflect gene expression. 

   Epigenetic features (DNA methylation) are linked to gene expression and can be tested in biological fluids, for example in blood (aka liquid biopsy).

  At this time DNA methylation is the most powerful tool for biomarker development in blood.  

Blood-based biomarkers in cancer are key for diagnosis and prediction of response—that’s why when it comes to project selection, we’re choosy. We want to give each of you the time and guidance you deserve to ensure successful discovery of biomarkers of your choice.  If you’re seeking the right partner or a special skillset, call us today. Together we’ll create and refine your plan for success. We didn’t get there alone. And neither will you. 


Biomarkers, cell-free DNA, epigenetics, methylation

Biomarkers in Medicine

A  biomarker is “a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention." 

 Clin Pharmacol Therapeutics. 2001;69:89–95 

Any objective measure can serve as a biomarker: probably the earliest one is fever as a marker of disease.

Biomarkers in Oncology

A wide variety of objective measures can be used: genetic and epigenetic, genomic, proteomic, lipidomic, immunological, olfactory (e.g. VOC - Volatile Organic Compounds), etc. Objective evaluation and precise identification of a disease and its response to therapy are essential criteria for a biomarker. 

Of course, how practical is the biomarker, how technologically uncomplicated is the process of its detection can make or break its clinical value.

Liquid Biopsy and Cell-Free DNA

Blood flows in the body and contacts every organ, and it is reasonable to seek biomarkers in blood. Cell-free DNA floats in the blood, carrying genetic (mutations) and epigenetic (DNA methylation) information about potential disease.

This information can be harnessed to detect the disease and to follow its reaction to treatment. Unlike tumor tissue, cell-free DNA can be repeatedly tested to collect the most up-to-date data. Unfortunately, there is not a lot of cell-free DNA in blood, so testing is a challenge.

Biomarker Strategies

Usually, scientists have an idea about where to look for a biomarker (hypothesis-driven plan). This makes the job easier, but what if the hypothesis is wrong? 

Alternatively, one can use unbiased (hypothesis-free) approach: looking at the whole universe of potentials, we select the best, the most accurate, and the most clinically appropriate.

DNA Methylation: the Good, the Bad, and the Ugly

   Good: DNA methylation is tightly linked to gene expression (real-time measure of disease), is stable, and each one of the millions of methylation sites can be a biomarker .

   Bad: if the DNA sample is very small, only a few sites can be tested by regular methods.

   Ugly: if you try to amplify DNA first, you strip away all methylation marks, so we need to test the initial sample.

Methylation of cell-free DNA

How to combine unbiased biomarker strategy and the wealth of knowledge provided by methylation in cell-free DNA?

We resolved this challenge with our M-Det technology: using 1 ng of cell-free DNA (three drops of blood) we test methylation in every fragment of the genome. Then we combine the best fragments  to use as a combinatorial (composite) biomarker.


Slide deck (pdf)


Selected files

A brief overview of DNA methytlation in cell-free DNA in blood as the media for biomarker development

Contact Us

Talevi Consulting


(708) 228-0407