Figure 1.

Estimation of TCR β-chain frequencies. (A) Serial dilutions of a T cell clone with known TCR β-chain sequence were mixed with 1 × 10⁷ unrelated T cells. The mixtures were analyzed by nested BV- and BC/BJ-specific PCR followed by hybridization with the TCR N-D-N-specific probe. (B) TCR β-chain frequencies were determined in a limiting dilution system. A TCR β-chain sequence was chosen arbitrarily from peripheral blood CD4 T cells, and a TCR N-D-N specific probe was designed. Multiple serially diluted CD4 T cell samples were probed for the presence or absence of the particular TCR β-chain sequence by TCR BV-BC- and BV-BJ-specific PCR and subsequent hybridization. The frequency of the TCR β-chain was determined from the slope of the curve to be 1 in 8 × 10⁵ CD4 T cells.