Flow cytometry analyzes a variety of properties of individual cells as they pass through laser beams. The method is very accurate and effective for measuring cellular parameters in complex subpopulations such as biomarkers, immunophenotyping, transfection for gene expression or cell-based phosphorylation, proliferation, cytokine detection or other potency assays. Flow Cytometry can determine the expression of specific intracellular or surface proteins in a specific population of cells in response to a drug.

Marin Biologic Laboratories Speak to a Scientist

Speak to a Scientist

We believe the best way to learn your needs is via a real time conversation. We always prefer to start with a discussion to assist you in meeting your goals. Click the orange button and we’ll get right back to you.

speak to a scientist


The FLOW method gates on cell size based upon forward and side scatter; thus mixed cell populations can be studied as with blood cells. Using FLOW cytometry enables a rapid analysis of the kinetics of drug action as well as the population of cells responding. Detection of cellular expression of molecules after drug treatment, both as concentration dependent and time dependent variables are typical experiments using FLOW. Because FLOW can identify multiple markers in a mixed cell population, it can be used for drug screening with multiple biomarkers, and as a high throughput screening assay. Readouts can be proliferation, apoptosis, death/cell cycle analysis, intracellular or surface markers, cytokine production and binding assays.


From the beginning and ongoing, your assay is a critical component of the life cycle of your current or eventual product. That is precisely why you want experience and expertise at the earliest possible stage of your development.

When you need an assay to prove your science and there is no commercial kit available, you need a custom assay. Our extensive expertise will quickly and methodically develop your assay to prepare it for eventual validation. Typically an assay can be developed from scratch in 5 or less experiments while minimizing any matrix effects.

We are firm believers in kits. The analytical portion of the assay itself is only a single component of what it takes to perform a successful experiment. It is all the other skills, experience and GLP/GMP conditions that we do day in and day out that will save you time getting to the results you actually want yesterday. We can create and distribute kits, too.

Many companies planning an IND submission or in Phase I/II may only require a well-qualified assay rather than a fully validated assay. You may or may not need GLP/GMP stringency and auditability yet. Our scientific team works with your scientists to qualify your assay for reproducibility, appropriate precision and accuracy.

To validate an assay is to measure precision, linearity, accuracy, robustness, system suitability and repeatability. To achieve these results, we conduct multiple experiments in a pre-validation phase with the assay. This phase is a series of 2-4 experiments that specifically look at these capabilities. Once we have advanced an assay, we perform the assay 2 more times for a total of 3 identical repeats. At that point, your assay meets the FDA GLP or GMP requirements.

Whether patient samples or drug product samples we will map out a timeline and follow through with sample receipts, meeting your regulatory needs at all points. We perform your assay as developed, qualified or validated, and promptly communicate the results and/or Certificate of Testing for any or all of your preclinical or clinical phases.

Knowing the importance to the FDA of lot release potency testing, our scientific team tests every manufacturing lot with your assay providing Certificates of Testing in a timely manner, under GMP Condition.

In order to determine shelf life for a particular drug substance, stability tests are performed at pre-determined calendar intervals. Our project coordinators communicate closely with you to anticipate the arrival of samples so as to have our staff and resources available for timely analysis and submittal of data and Certificates of Testing.

It’s your data

Many of our Clients are grateful that we are willing to supply the raw data or analyzed data. Whether we are working with various populations of cells in a mixed culture such as blood cells from in vitro studies or we are working on in vivo toxicology projects, we always strive to provide as much information as we have gained through the course of the work done on your behalf.