Analysis of human metaphase chromosomes using antibodies to double-stranded and single-stranded DNA: staining patterns are related to DNA conformation.

Fresh and 6-day-old fixed chromosome spreads, both untreated and treated with various banding techniques and nucleases, were stained using monoclonal antibodies to double-stranded and single-stranded DNA. DNA in fixed chromosome preparations became progressively denatured with ageing. The staining pattern of untreated chromosomes with anti-double-stranded DNA antibodies (which resembles G-banding) was determined by the conformation of the chromosomal DNA.