[twic]

> You isolate the B cells by limiting dilution and/or immortalize them by fusion with a special type of cell to make a hybridoma to isolate clonal populations of single cells that are maintainable. Then you test each clonal population for whether it produces the antibody of interest

Do people actually still do it this way? I would have thought that you would use more targeted approaches where you use an antigen to fish for cells of interest before culturing. There are a few such techniques described here:

https://www.frontiersin.org/articles/10.3389/fimmu.2019.0169...

Naively, i would have thought you could do something with affinity columns or magnetic beads, too - coat beads with antigen, then use those to extract B cells expressing a matching surface immunoglobulin.

[biophetik]

Magnetic bead filteration is commonly used to filter immune cells, but they are expensive. I used to work for a lab that did this on a daily basis. Common problems with it were getting enough cells to run the assays, and the process of extraction is damaging to the cells. So you need a lot of starting material and then after that they don't stay alive for very long. You can treat and freeze after isolation but thawing only decreases the amount of healthy cells.