Gene transfer and cancer / editors, Mark L. Pearson and Nat L. Sternberg.

Date:
[1984], ©1984
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Gene transfer and cancer / editors, Mark L. Pearson and Nat L. Sternberg. Source: Wellcome Collection.

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    24 CHROMOSOME MAPPING AND GENE TRANSFER FIGURE 1. Chinese hamster micronucleated cells. Micronucleation induced by DMSO treatment. classes can also be separated by filtration through nucleopore filters with pore diameter of 1 to 5 pg (19). Microcells prepared from GT-1, GT1-2, and GT8-2 were size fraction¬ ated and fused with mouse hprt cells in a series of experiments. Microcell fusion was performed by the described procedures using poly¬ ethylene glycol (4) or inactivated Sendai virus (23), and microcell hybrids were isolated by selection in HAT medium (13). In one set of experiments, when the smallest size class of microcells from GT1-1 and GT1-2 were fused with mouse TG8 (hprt~) cells, we recovered two hybrid clones. These hybrids originated with a frequency of 10^. In a second series of experiments, microcells prepared from GT8-2 cells were fused with mouse RAG (hprt~) cells. In these experiments, eight different size classes of fractionated microcells were fused sepa¬ rately with the recipient cells, and we recovered a total of 22 hybrids. The frequency of hybrids recovered (10^) in these experiments was an order of magnitude higher than in previous ones. The increase in the frequency of hybrid formation in the second series of experiments is attributed to shorter mitotic arrest used for the induction of micronu¬ cleation (data not shown). Analysis of Microcell Hybrids All microcell hybrids were analyzed cytologically by a sequential staining procedure involving Giemsa banding followed by Hoechst 33258 fluorescent staining (12). Mouse chromosomes display a characteristic