Six-year-old archival chromosome preparations are still good biological reagents for repeated primed in situ labelling (rPRINS).

Six-year-old chromosome preparations of Eulemur coronatus were used for in situ localization of highly repetitive DNA sequences. The application of the repeated primed in situ labelling (rPRINS) technique allowed the detection of positive signals whereas conventional fluorescence in situ hybridization gave negative results on the same archival preparations. This paper reveals the possibility of rescuing archival chromosome preparations for both clinical and comparative cytogenetics. Moreover, the chromosomal localization of the ECO-SAT 503 bp highly repetitive DNA sequences were found to localize in the pericentromeric region of every chromosome, with the exception of chromosome 9.