A biomarker is a defined characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or biological responses to an exposure or intervention, including therapeutic interventions(1). With the development of innovative and personalized therapies, biomarker tracking is increasingly important to support the clinical development…

Due to its ability to analyze multiple parameters across different cell types within a sample, flow cytometry provides rich and clinically valuable data sets from even small volumes of blood. However, flow cytometry is a challenging platform to master, and requires significant investment in equipment and technical training.

For most applications flow cytometry is used to identify cell populations and define bivariant terms of positive and negative sub-populations according to specific biomarkers, through the binding of fluorescently tagged monoclonal antibodies (mAbs). Typically, the cutoff between these populations is set relative to a control unstained population. Since the fluorescent intensity of a signal is proportional to the amount of monoclonal antibody bound to that cell target, this signal is directly related to the expression level of that target. However, for flow cytometry endpoints to be considered truly quantitative and fulfill the rigor of clinical utility, several obstacles needed to be overcome. In this blog, we explore the rationale behind quantitative flow cytometry, and the tools that are now being implemented to help achieve standardization.

Introduction of CAR-T Therapy T lymphocytes are engineered with synthetic receptors known as chimeric antigen receptors (CAR) in CAR-T Cell therapy. The CAR-T cell is an effector T cell that recognizes and eliminates specific cancer cells, independent of major histocompatibility complex molecules. (Zhai et al. 2018). Chimeric antigen receptors (CARs) cells have recombinant receptor constructs expressed in T cells to target cells expressing specific antigens.

Flow Cytometry utilizes fluorescently labeled antibodies to detect specific biomarkers on the surface and within cells, and over the past few years, there has been a surge in reagents available for flow cytometry applications. Most of these have been developed using monoclonal antibodies raised in mice and conjugated to a range of fluorophores. However, there are still instances where suitable monoclonal antibody reagents/conjugates are not commercially available, and small-scale conjugations are not practical. In these instances, so-called indirect staining may be employed, where the binding of an unconjugated primary antibody is detected using a secondary anti-IgG antibody conjugate.

With the rapid progress of immune-modulating drug development, flow cytometry has found itself increasingly at the forefront of clinical trial assessment of safety and efficacy. This is not without challenges since flow cytometry analysis can be complicated and expensive, too often employs idiosyncratic experimental and analytical methods. So how can a platform without standardized methods and processes, be successfully applied to evaluate clinical endpoints?

Due to its ability to analyze multiple parameters across different cell types within a sample, flow cytometry can provide very rich and clinically valuable data sets from even small volumes of blood. However, flow cytometry is a challenging platform to master, and requires significant investment into equipment and technical training. So, for many researchers, outsourcing flow cytometry to a Contract Research Organization (CROs) is both cost-effective and the best way to ensure the highest quality of data from their samples. So, what types of flow cytometry applications are the most outsourced to CROs?

Immuno-oncology is a growing field. The goal is to augment the patient’s immune system to attack the cancer cells. The current lines of treatment for cancer are radiation, chemotherapy, and surgical resection. If these treatments do not work, physicians can seek alternative treatments, such as immune-oncology therapeutics. Two emerging immune-oncology…