Spectratypes of the T-cell repertoire during the first year after autologous transplantation with FACS-purified CD34⁺ HPC. PBLs were analyzed using CDR3 spectratyping and multiparameter flow cytometry to ascertain the Vβ TcR repertoire from an individual patient at the time points shown. Histograms of the relative sizes of the PCR-amplified CDR3 region for five representative Vβ TcR gene products are shown. Numbers in the upper right corner of each box represent the percentage of cells expressing a specific Vβ TcR. The scale of the y-axis varies in each small box according to the maximal peak amplitude, which is proportional to the quantity of RNA bearing the specific Vβ TcR. The x-axis represents the nucleotide length of the PCR-amplified TcR gene products.