A monoclonal antibody-based immunoassay for the polyamines spermine and spermidine.

has extensive and well-developed Golgi apparatus. This is particularly important in the application of C23/11 as a fusion partner in human monoclonal antibody production. The electron micrograph studies also confirmed this excentric nucleation pattern. lrnmunohistochemical analysis of the paraproteins secreted by C23/11 showed that both K and 1 chains were present. Some reports have shown that this may be a differentiation effect in culture, but, alternatively it may be due to cross-reactivity of the analytical antibodies being used in this analysis or the growth of two different myeloma populations. Repeat studies are necessary to confirm this. lsoenzyme analysis has also been carried out on C23/11. The results of this analysis are summarized in Table 1. C23/ 11 has an exceptionally fast growth rate which is atypical of a myeloma cell. Growth rate experiments on early passage cells ( P = 4) showed a doubling time of between 12 and 15 h. Attempts to culture C23/11 in RPMI medium with lower FCS concentrations altered this doubling time significantly. I t also appears that the growth rate is slower in later passage cells (P= 25). Further characterization studies into the cytogenetics of C23/11 and a completion of the investigation of the associated 'M' protein are currently being undertaken. Human monoclonal antibody production has been hindered by the lack of availability of human myeloma fusion partners. The fast doubling time, degree of Golgi apparatus and ease of growth in vitro make C23/11 an interesting potential fusion partner. We hope to investigate this fusion potential with mouse myeloma cells by both chemical fusion and electrofusion in the near future.