How does one isolate a specific antibody from the blood? Presumably there are thousands (millions?) of different ones in there for all kinds of pathogens.
Typically, you first test the blood to see if there are any antibodies in that blood of interest. E.g., collect blood sample, harvest serum from blood by coagulation and centrifugation, apply serum to surface coated with COVID protein(s), wash away unbound material, detect whether antibodies to serum have bound to surface coated with COVID proteins. If yes, then this is a blood sample of interest. You could also test for neutralizing antibodies in parallel/before/after/instead in a viral replication assay. Once you have identified the blood as containing what you want, you then harvest more and collect mature B cells. Mature B cells each produce one antibody. 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, isolate the nucleic acid that encodes that antibody and put it into a cell type suitable for manufacturing. There are other ways to do it, but the above is fairly standard. It is laborious and easy to mess up and takes time (1 to 2 months) to do correctly. Any step can go wrong and require starting over.
> 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:
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.
Here’s a noob question. The coronavirus is made out of a whole bunch of proteins. Have we fully mapped out all the protein structures and corresponding DNA code?
The antigen is also a protein, I assume the DNA sequence for it is well known. Right?
How far are we in terms of tech to print custom proteins from arbitrary DNA sequences?
Is understanding protein folding and protein to protein interaction the holy grail of making massive improvements in molecular biology? What are the big unsolved problems?
Like if we know the virus’s DNA and it’s 3D protein architecture, we can solve for antigen proteins in a computer that outputs possible DNA sequences and we can manufacture them the next day in a protein printer. How far away are we to that future?
> It is laborious and easy to mess up and takes time (1 to 2 months) to do correctly.
Sounds like a manual software testing. What are the chances of automating entire process? Whenever I see bio/chemists working it seems very manual job. I assume someone already tried it, but perhaps only for specific area rather than making universal robot?
IIRC the virus was isolated last year, so wouldn't at least some antibodies have been identified by now? Or, it's just very common to have to start over?
Is it unusually difficult for this coronavirus? eg I've heard it's unusually large.
hcknwscommenter|5 years ago
twic|5 years ago
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.
nojvek|5 years ago
The antigen is also a protein, I assume the DNA sequence for it is well known. Right?
How far are we in terms of tech to print custom proteins from arbitrary DNA sequences?
Is understanding protein folding and protein to protein interaction the holy grail of making massive improvements in molecular biology? What are the big unsolved problems?
Like if we know the virus’s DNA and it’s 3D protein architecture, we can solve for antigen proteins in a computer that outputs possible DNA sequences and we can manufacture them the next day in a protein printer. How far away are we to that future?
martimarkov|5 years ago
Any materials you can recommend for complete novices in industrial biology processes?
dzhiurgis|5 years ago
Sounds like a manual software testing. What are the chances of automating entire process? Whenever I see bio/chemists working it seems very manual job. I assume someone already tried it, but perhaps only for specific area rather than making universal robot?
hyperpallium|5 years ago
Is it unusually difficult for this coronavirus? eg I've heard it's unusually large.
WhiteSage|5 years ago
dukoid|5 years ago