A novel cell line, L1236, was established from the peripheral blood of a patient with Hodgkin's disease (HD). Two Ig VH and one Vkappa gene rearrangements were amplified by polymerase chain reaction (PCR) from the DNA of this cell line, demonstrating its derivation from the B-cell lineage. To test the cell line for its clonal relationship to the Hodgkin/Reed-Sternberg (H-RS) cells in the patient, single H-RS cells were micromanipulated from tissue sections of a tumor-infiltrated bone marrow specimen from that patient and analyzed by PCR for Ig gene rearrangements. The same rearrangements detected in the cell line were also found repeatedly in H-RS cells of the biopsy material. Thus, L1236 is the first cell line established from a case of HD for which a derivation from the H-RS cells of the patient could be demonstrated. Furthermore, the selective isolation of identical V gene rearrangements from multiple single H-RS cells demonstrates that these cells represented a clonal population in the patient.