RESUMO
Cell lines established from African green monkey kidney cells have been used over years in virology. It is possible to distinguish them by detailed karyology of banded metaphases or by iso-enzyme studies. Different morphology of NOR-bearing chromosomes in three African green monkey cell lines studied in our laboratory enables us to distinguish them in simple conventionally Giemsa-stained slides. Vero cells have two chromosomes with secondary constrictions with active NORs. One chromosome is a small submetacentric with secondary constriction on the long arm in the vicinity of centromere. The second one is rather metacentric with a smaller secondary constriction. In BGM cells we found two submetacentric chromosomes, one has a large secondary constriction, the other has a smaller secondary constriction. BS-C-1 cells have a large metacentric chromosome with secondary constrictions on both arms. In one investigation an additional large acrocentric chromosome with the secondary constriction on the long arm was found. Comparison with morphology of NOR-bearing chromosomes in a Rhesus monkey cell line is discussed. The method described here is particularly useful for a rapid discrimination of cell lines, produced in our Institute, for virological and diagnostic application in virological laboratories of the hygiene service and in hospitals.