Cell culture is an integral part of genetic studies, including cytogenetic, metabolic, and DNA analyses. Standard culture procedures used today involve plating minced tissue explants in dishes and waiting 3 to 4 weeks for adequate growth. We describe a method that utilizes collagenase digestion of tissue biopsies, enabling cell harvest as soon as 3 days after culture initiation; this has been used successfully in our laboratory for cytogenetic and metabolic studies. Culture duration can be controlled by the cell plating density. Although collagenase digestion of tissues is commonly used in cytogenetics laboratories for tumor or chorionic villous dissociation, we have found that few labs have considered using this rapid and efficient procedure for routine tissue samples.