Electrokaryotypes of eleven clones of the ciliated protozoan Paramecium caudatum were obtained by means of pulsed field gel electrophoresis (PFGE) and analyzed using the densitometry and Southern blot hybridization techniques. The main characteristics of the spectra of macronuclear DN A fragments from different clones were identical. Southern hybridization with the sequences complementary to the telomerase RNA component and calmodulin genes showed that these genes were located in macronuclear DNA fragments of similar size in all clones studied. The interclone polymorphism was demonstrated only for the number and position of the bands corresponding to hyperamplified molecules. Quantitative analysis of the macronuclear DNA spectra from different P. caudatum clones was conducted. The total number of DNA molecules per macronuclear subgenome was estimated at 230 ±40. The kinetic complexity of a macronuclear genome is discussed.