CFU-GEMM, multipotent progenitor cells, give rise to erythroid, granulocyte-macrophage and megakaryocytic cells. We have examined the utility of this assay for predicting hematologic recovery in patients treated with high-dose chemotherapy and autologous marrow rescue with cryopreserved marrow. In marrow samples from 50 patients CFU-E, BFU-E and CFU-GEMM significantly decreased following cryopreservation. The median value for CFU-E declined from 132,659 to 10,648, BFU-E decreased from 36,112 to 3345 and CFU-GEMM decreased from 3242 to 260 colonies per ml of marrow frozen. Once cryopreserved, the number of CFU-E, BFU-E and CFU-GEMM remained stable with prolonged storage in liquid nitrogen. In 48 patients uniformly treated with high-dose melphalan (180 mg/m2) and rescued with cryopreserved autologous marrow, univariate analyses showed that the time to platelet recovery (greater than 50 x 10(9)/l) was correlated with the number of CFU-E, BFU-E and CFU-GEMM infused (p less than 0.05). The time to neutrophil recovery was only correlated with the number of BFU-E and CFU-GEMM infused (p less than 0.01). However, by multivariate analyses, only the number of CFU-GEMM, and not CFU-E and BFU-E, infused correlated both with the time to neutrophil and platelet recovery. These data indicate that the CFU-GEMM assay may be useful for determining the repopulating ability of cryopreserved bone marrow.