LASER RAMAN MICROSCOPY OF CHROMOSOMES IN LIVING EUKARYOTIC CELLS - DNA POLYMORPHISM IN-VIVO

In order to answer the question of what the structure of DNA is in the nucleus of a living cell where its long length must be subjected to r epeated folds in order to pack it into such a small space, a laser Ram an microscope was designed and built to take the Raman spectra of DNA in the packaged state in which it occurs in nature. Spectra were taken of the DNA in salmon sperm, squid sperm and the nucleus of the saliva ry gland of Drosophila melanogaster. These measurements show that the majority of the deoxynucleotide residues in the DNA in the nucleus bel ongs to the B-type family of conformations. However, the DNA in the nu cleus may have a different furanose ring pucker than it does in soluti on, which may be evidence of some significant polymorphism.