Cytogenetic analysis of bone marrow and peripheral blood samples stored in fixative for several years.

We have developed a method which improves the spreading of chromosomes and permits banding analysis of cytogenetic samples of bone marrow and unstimulated peripheral blood which have been stored in fixative for up to 15 years. Metaphase cells had been harvested as usual and stored in fixative (acetic acid:methanol 1:3) at -15 C. The procedure includes 4-5 changes of fixative (acetic acid:ethanol 1:1). Next, cells are dropped onto a chilled, wet slide. The back of the slide is then rinsed with 70% ethanol and dried by ignition. C-, G-, Q-, or R-banding patterns can new be obtained with these specimens. The procedure is useful for reinvestigation of cytogenetic sample that were obtained prior to the development of banding techniques.