<prompt> True about Hybridoma : PGI Dec 2008Immortalise myeloma cellHybridoma cell produced by fusion of T-cell myelomaCell is of human originPrior immunisation is done  <response>: Ans : A Immortalise myeloma cell; D Prior I immunisation is done E Produce monospecific.. I Cell Lineage in Hybridoma-Harper27th604The myeloma ceils are immortalized, do not produce Ab are HGPRT Hypoxanthine-guanine phosphoribosyl transferase rendering the salvage pathway of purine synthesis inactiveThe B cells are not immortalized, each produce a specific j Ab St they are HGPRTThe resulting hybridoma ceils are immortalized via the j parental myeloma cells, produce Ab St HGPRT both latter properties gained from the parental B cellsB celt will die because they are not immortalized. In the presence of HAT hypoxanthine, aminopterin St thymidine, the myeloma cells will also die, since the aminopterin in HAT suppresses purine synthesis by the de novo pathway by inhibiting reutilization of tetrahydrofolate.However, the hybridoma cells will survive, grow because they are HGPRT if cloned-produce monoclonal Ab.Hybridoma TechniqueIt was developed by Kohler MilsteinQB celt are obtained from Spleen of mouse or other suitable animal previously injected with an Ag or mixture of antigens eg. foreign cellsIn this large amount of a single monoclonal Ab specific9 for one epitope can be obtainedThe method involve cell fusion in presence of polyethylene glycol St resulting permanent cell line is called a hybridomaThe hybridoma cells can be frozen stored St subsequently thawed when more of the Ab is required, this ensures its longterm supplyThe hybridoma cell can also be grown in the abdomen of mice providing relatively large supply of Ab.Application of hybridoma technique :To determine the nature of infective agentQThey can be used to measure individual protein eg. plasma proteinTo subclassify both normal eg lymphocyte tumour cell eg leukaemia cellUsed in autoimmune ds eg. Rheumatoid arthritisUsed for blood groupingQTo accelerate removal of drugs from circulation when they reach toxic level eg. digoxin Proliferation -ve Igs secretion HAT resistant HGPRTase unfused normal cell dieSplenic cells from mouse immunized with specific antigen Mouse myeloma cells Proliferation Igs secretion -ve HAT sensitive HGPRTase-ve- - Cell fusion inPEG-1500 ,r - Fused cells Microtiter plates in HAT selective medium Cells are coloned and subcloned in plates containing small wells 8 to 10 days time -Lymphocytes hybrid develophvbridoma cells Supematent medium tested for specific desired monolconal antibody 