Single-strand conformation polymorphism analysis of TCR Vβ21 cDNA amplified with the PCR. The cDNA from BMMC of a normal individual, BMMC of the patient, and the three Vβ21⁺ T-cell clones were amplified with the PCR, using a primer specific to Vβ21 and a Cβ primer. The amplified products were heat-denatured in a formamide solution and electrophoresed on an 8% polyacrylamide gel. The DNA was visualized by silver staining.