6 ms·

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.

WhiteSage 6y ago
It sticks to a virus protein, so you can use that virus protein to find it!
- dukoid 6y ago
  Is synthetisizing antibodies a thing? Is it hard? If so, why?
  - fabian2k 6y ago
    They're far too large and complex to be synthesized from scratch, that is simply not possible. They are produced in various biological systems, with nature doing the synthesis. As far as I understand you can scale that up reasonably well with some effort.
    - Symmetry 6y ago
      It's too large and complex to do now but I bet we'll be able to do that sort of thing by 2040.
      - est31 6y ago
        Maybe even by 2030 if the coronavirus causes an expansion of research. Which it'll likely do.
      - woofie11 6y ago
        I have a friend who runs a company which genetically engineers cells to make chemicals for a living. This doesn't seem like 2040-era science fiction. Indeed, I'm not sure it's out-of-scope for 2020-era technology.
        nojvek 6y ago
        What is the said company ?
        woofie11 6y ago
        Ginko Bioworks. Apparently it's grown quite a bit since I've spoken to my friend. When we last checked in, it was a little startup. Now, it's a $2.4 billion dollar operation. I guess my friend is probably worth a few hundred million right now.
      - koheripbal 6y ago
        The reason it's not researched much is because giving someone an antibody will not confer immunity - it will only treat the immediate virus. It has value, but there are usually better treatments available that more broadly fight a variety of viruses and don't need to be so specifically customized as an antibody.
        dukoid 6y ago
        I suppose testing would be easier for a cure (compared to a vaccine)? Given that only the "adapter" needs to be specialized, I was wondering why there don't seem to be any approaches based on antibody mass-production....
        deleted 6y ago
        [deleted]
    - johnthealy3 6y ago
      To add to this, you don't even need to know what the antibody looks like, or even if it exists. Very simplified example: It's possible to grow a dish of cancer cells (because they divide quickly and are immortal, e.g HeLa cells), "purify" away everything that isn't protein (cell lysis), then run the proteins through a gel that separates them by size (Western blot). Comparing these to a control will show you which proteins enabled survival, which gives you your candidates for sequencing and further tests. However, right now we have humans synthesizing large amounts of antibodies that are proven to work (because the humans creating them survived and cleared the virus). It may ultimately be faster to isolate antibodies from the serum and engineer cell cultures (through adding DNA to them, "recombinant DNA") to create more of those antibodies, resulting in much stronger synthesis of a single antibody (so-called "monoclonal antibody drugs"). It's nearly certain that both of these are happening many times over around the world right now. All of the science here was already in lab use the first time I worked in a bio lab in 2003, and nowadays we have methods that didn't exist then (such as CRISPR for DNA manipulation and fast sequencing of both nucleic acids and proteins).
hcknwscommenter 6y ago
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.
- martimarkov 6y ago
  Honestly I think I learned more from this one comment that most of my biology classes. :D Any materials you can recommend for complete novices in industrial biology processes?
- hyperpallium 6y ago
  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 6y ago
    Antibodies have been identified by now. They are being tested as we speak. Coronavirus is not more difficult than any other target really. It just takes time.
- twic 6y ago

WhiteSage 6y ago

It sticks to a virus protein, so you can use that virus protein to find it!

dukoid 6y ago
Is synthetisizing antibodies a thing? Is it hard? If so, why?
- fabian2k 6y ago
  They're far too large and complex to be synthesized from scratch, that is simply not possible. They are produced in various biological systems, with nature doing the synthesis. As far as I understand you can scale that up reasonably well with some effort.
  - Symmetry 6y ago
    It's too large and complex to do now but I bet we'll be able to do that sort of thing by 2040.
    - est31 6y ago
      Maybe even by 2030 if the coronavirus causes an expansion of research. Which it'll likely do.
    - woofie11 6y ago
      I have a friend who runs a company which genetically engineers cells to make chemicals for a living. This doesn't seem like 2040-era science fiction. Indeed, I'm not sure it's out-of-scope for 2020-era technology.
      - nojvek 6y ago
        What is the said company ?
        woofie11 6y ago
        Ginko Bioworks. Apparently it's grown quite a bit since I've spoken to my friend. When we last checked in, it was a little startup. Now, it's a $2.4 billion dollar operation. I guess my friend is probably worth a few hundred million right now.
    - koheripbal 6y ago
      The reason it's not researched much is because giving someone an antibody will not confer immunity - it will only treat the immediate virus. It has value, but there are usually better treatments available that more broadly fight a variety of viruses and don't need to be so specifically customized as an antibody.
      - dukoid 6y ago
        I suppose testing would be easier for a cure (compared to a vaccine)? Given that only the "adapter" needs to be specialized, I was wondering why there don't seem to be any approaches based on antibody mass-production....
      - deleted 6y ago
        [deleted]
  - johnthealy3 6y ago
    To add to this, you don't even need to know what the antibody looks like, or even if it exists. Very simplified example: It's possible to grow a dish of cancer cells (because they divide quickly and are immortal, e.g HeLa cells), "purify" away everything that isn't protein (cell lysis), then run the proteins through a gel that separates them by size (Western blot). Comparing these to a control will show you which proteins enabled survival, which gives you your candidates for sequencing and further tests. However, right now we have humans synthesizing large amounts of antibodies that are proven to work (because the humans creating them survived and cleared the virus). It may ultimately be faster to isolate antibodies from the serum and engineer cell cultures (through adding DNA to them, "recombinant DNA") to create more of those antibodies, resulting in much stronger synthesis of a single antibody (so-called "monoclonal antibody drugs"). It's nearly certain that both of these are happening many times over around the world right now. All of the science here was already in lab use the first time I worked in a bio lab in 2003, and nowadays we have methods that didn't exist then (such as CRISPR for DNA manipulation and fast sequencing of both nucleic acids and proteins).

hcknwscommenter 6y ago

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.

martimarkov 6y ago
Honestly I think I learned more from this one comment that most of my biology classes. :D Any materials you can recommend for complete novices in industrial biology processes?
hyperpallium 6y ago
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 6y ago
  Antibodies have been identified by now. They are being tested as we speak. Coronavirus is not more difficult than any other target really. It just takes time.
twic 6y ago