Methods and compositions for chromosome-specific staining

Abstract

The invention relates generally to the field of cytogenetics, and more particularly to methods for identifying and classifying chromosomes.

Description

RELATED APPLICATION [0001] This application is a continuation in part of U.S. Ser. No. 819,314, filed Jan. 16, 1986 by the named inventors hereof and assigned to the same assignee and claims priority in said prior filed application.[0002] The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California, for the operation of Lawrence Livermore National Laboratory.BACKGROUND OF THE INVENTION [0003] The invention relates generally to the field of cytogenetics, and more particularly, to methods for identifying and classifying chromosomes. [0004] Chromosome abnormalities are associated with genetic disorders, degenerative diseases, and exposure to agents known to cause degenerative diseases, particularly cancer, German, “Studying Human Chromosomes Today,”American Scientist, Vol. 58, pgs. 182-201 (1970); Yunis, “The Chromosomal Basis of Human Neoplasia,”Science, Vol. 221, pgs. 227-236 (1...

AI Technical Summary

Benefits of technology

[0018] It is desirable to disable the hybridization capacity of repetitive sequences because copies occur on all the chromosomes of a particular organism; thus, their presence reduces the chromosome specificity of the staining reagents of the invention. As discussed more fully below, hybridization capacity can be disabled in several ways, e.g., selective removal or screening of repetitive sequences from chromosome specific DNA, selective blocking of repetitive sequences by pre-reassociation with complementary fragments, or the like.

[0023] The present invention addresses problems associated with karyotyping chromosomes, especially for diagnostic and dosimetric applications. In particular, the invention overcomes problems which arise because of the lack of stains that are sufficiently chromosome-specific by providing reagents comprising heterogeneous mixtures of labeled nucleic acid fragments that can be hybridized to the DNA of specific chromosomes, specific subsets of chromosomes, or specific subregions of specific chromosomes. The staining technique of the invention opens up the possibility of rapid and highly sensitive detection of chromosomal abnormalities in both metaphase and interphase cells using standard clinical and laboratory equipment. It has direct application in genetic screening, cancer diagnosis, and biological dosimetry.

Problems solved by technology

Thus, if these repeats form a sizable fraction of a chromosome, and are removed from the heterogeneous mixture of fragments employed in the invention, perfect uniformity of staining may not be possible.

Images