Question

I am doing research on CAR T-cell kinetics. The measurement of CAR T-cell concentrations across time is normally carried out with qPCR (see here, Fig. 1). These concentrations are generally reported as transgene per microgram of DNA. My question is how to go from this number to a cell count estimate, for example cell per microliter of blood, which is sometimes reported (see here, Fig. 3).

I understand this should be done with three conversion factors:

transgene/microgram * microgram/cell * cell/microliter * CAR cell/transgene = CAR cell/ microliter

I don't think the first two factors are hard to obtain, but I don't know about the third. I don't even know if this is right at all. Is there a straightforward or standard way to make this conversion?

Answer 1

To convert transgene per microgram of DNA to cell per microliter, flow cytometry can be used to quantify the cells and determine the cell count per microliter of blood.

Step-by-step explanation:

In order to convert transgene per microgram of DNA to cell per microliter, you need to know the third conversion factor which is cell/microliter. One common method to estimate cell counts is by using flow cytometry. Flow cytometry is an automated cell counting system that can detect specific cells as they pass through a narrow tube one cell at a time. By labeling the CAR T cells with a fluorescently labeled antibody, you can quantify the cells and determine the cell count per microliter of blood. This method is often used to measure the level of specific cells, such as CD4 T cells, in blood samples.