Hybridoma propagation methods — in vitro vs. in vivo How can monoclonal antibody–producing hybrid cells (hybridomas) be propagated for antibody production?

Introduction / Context:
After fusing antibody-producing B cells with myeloma cells, hybridomas must be expanded to yield monoclonal antibodies. Understanding the two classical production routes informs ethical considerations and scale-up strategies in biotechnology.

Given Data / Assumptions:

• Hybridomas are immortalized antibody-secreting cell lines.
• Production can be performed in vitro (flasks, bioreactors) or in vivo (ascites).
• Choice depends on yield, purity, ethics, and regulatory expectations.

Concept / Approach:
Historically, ascites production in mice yielded high antibody concentrations but raises animal welfare concerns and potential contaminants (host immunoglobulins, proteases). Modern practice favors serum-free in vitro systems, roller bottles, or stirred-tank bioreactors for controlled, scalable, and ethical production. Both approaches are technically valid ways to propagate hybridomas.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturing guidelines and lab manuals outline hybridoma culture systems and detail the decline in ascites use in favor of in vitro methods for GMP compliance.

Why Other Options Are Wrong:

• Only in vitro or only in vivo excludes a valid method.
• None/bioreactor-independent diffusion: inaccurate; practical propagation requires culture systems.

Common Pitfalls:
Assuming ascites is obsolete; while discouraged, it is still technically possible in some settings. However, expect in vitro systems in modern labs.

Final Answer:
Both (a) and (b)