[The analysis of chromosomes today: aspects of the technic with indications and importance of the method].

0.5 to 1% of all newborn possess a chromosomal aberration. In a growing number of neoplasias chromosomal disturbances become known. 10 years after the introduction of the band technique into cytogenetics this method must be regarded as most essential progress in the description of chromosomes. Apart from the exact identification of each individual chromosome the band technique allows the exact establishment of fraction points and gives the possibility of new progress in the gene tabulation. With the help of instances some of these possibilities are demonstrated. Prerequisite for the effective use of the analysis of chromosomes is a strong indication. An indication catalogue concerning the clinical application of the method summarizes the essential problems from paediatrics, gynaecology and internal medicine.