ABSTRACT
The isolation procedure is often adopted, not only for the chemical analysis of chromosomes but also for culturing the nuclei and chromosomes in natural or synthetic media as well as for cloning. The technique for micrurgical isolation was initially developed with respect to the salivary gland chromosomes of Diptera, where puffing at different segments in different phases of development provided adequate proof of the genetic control of differentiation and the change of pattern following treatment with different agents. Similarly, chromosomes can be donated to the host cytoplasm by taking out a chromosome, rolling it into a bundle and pushing it through the slit of the host cell. Microdissection of chromosomes in recent years has become a very elegant technique for chromosome manipulation and fragment cloning. Microdissection of polytene chromosomes of Drosophila with fine glass needle and of human chromosome with laser beam has facilitated cloning of specific gene sequences.
