Chemotherapy and radiation treatments can be life-saving for patients with cancer, but they have harsh side effects that can been felt and seen throughout the body. There can also be unseen consequences: These important treatments can mutate DNA and damage chromosomes in patients’ cancerous and noncancerous cells alike. When this occurs in a germline cell (eggs in women and sperm in men), it can lead to serious fetal and birth defects in a resulting pregnancy. In a study published in PLOS One, a team led by Biological Systems and Engineering (BSE) Division senior scientist Andrew Wyrobek reported success adapting an established cellular DNA analysis technique called fluorescence in situ hybridization (FISH) to probe sperm DNA for a wide variety of chromosomal defects simultaneously.