<prompt> In monoclonal antibody production, monoclonal cells are differentiated from?Sensitized B cellsSensitized T cellsMyeloma cell linesNone of these  <response>: ANSWER: C Myeloma cell linesREF:Applications and engineering of monoclonal antibodies by David J. King page 17, A practical guide to monoclonal antibodies by J. Eryl Liddell, Anthony Cryer Page 69A myeloma cell is classically defined as a neoplastic plasma cell in myelomatosis producing a structurally and electrophoretically homogeneous monoclonal paraproteinFusion of the myeloma cells and the harvested B cells is usually accomplished using polyethylene glycol PEG as an agent to induce membrane fusion cheep, reliable and most commonly used method. Alternatively electrofusion or Sendai virus can be used. After fusion a mixture of spleen cells myeloma cells and hybridoma cells are present and next step is selection of hybridoma cells over other cellsPOST FUSION SELECTION:Myeloma cells are deficient in HGPRT and are not able to use salvage pathway for RNA synthesis. HAT Hypoxanthine, Aminopterin, Thymidine medium is used to achieve selection. Aminopterin is an inhibitor of DNA and RNA synthesis and thus blocks myeloma cells. Hybridoma cells however have HGPRT and thus can add hypoxanthine and thymidine to produce RNA and thus can survive.Cell typeDNA synthesisSurvival in HAT medium Salvage pathwayDe Novo pathway MyelomaHGPRT-Aminopterin sensitiveDie no DNA symthesisSpleenHGPRT Aminopterin sensitiveDie finite survival in vitroMyeloma spleen hybridHGPRT Aminopterin sensitiveLiveMyeloma myeloma hybridHGPRT-Aminopterin sensitiveDie no DNA symthesisSpleen spleen hybridHGPRT Aminopterin sensitiveDie finite survival in vitroAlternatively myeloma cells can be selected to be deficient in enzyme thymidine kinase TK by growth in bromodeoxyuridine. 