Mosaic karyotypes are present in at least 0.3–1% of the clinical cases analyzed by banding cytogenetics. It is well known that the pattern of mosaicism can vary greatly in different tissue types from the same patient. However, normally a maximum of two different tissues from a child or an adult are studied cytogenetically, i.e., peripheral blood and skin fibroblasts. Preparation protocols for three further tissues are presented here. All three are easy to obtain, and the resulting preparations of interphase nuclei can be used in routine interphase FISH applications. A summary of how to treat buccal smears, hair root cells or urine before the FISH procedure is also provided.
