Human gonadal stromal cell pellets are derived from testes that have been dissociated into a single cell suspension, cultured, and snap frozen. Human gonadal stromal cell pellets are from a single donor. These cell pellets enable researchers to investigate reproduction, stem cells, and disease at the molecular level. In addition, these cell pellets may be used for developmental studies. Robertsonian translocation (RTL) is a common form of chromosomal rearrangement that in humans that occurs in the five acrocentric chromosome pairs. People with RTL have only 45 chromosomes in their cells with all essential genetic material present. They appear normal, however their children may be either normal and carry the fusion chromosome, or they may inherit a missing or extra long arm of an acrocentric chromosome causing disorders such as Down syndrome.