Seroreactivity to purified GD21-1 and BA21 recombinant proteins. Representative Western blots displaying the reactivity of nine CD3⁻ LGL patients (strips labeled 3, 5 through 8, 10 through 13) to HTLV-I gp21 recombinant proteins. All purified proteins were blotted at a concentration of 2 μg/cm nitrocellulose and sera were diluted and incubated as described.12 Strips containing BA21 (molecular weight ∼ 30 kD) coelectrophoresed with GD21-1 (molecular weight ∼ 15 kD) are indicated by the letter G at the bottom. Strips containing nonrecombinant sj26 are indicated by the letter S. The migration of BA21 and GD21-1 are indicated at right. Nonrecombinant sj26 has a molecular weight of 26.5. The strips labeled H-I were incubated with sera from an HTLV-I infected individual. The lanes marked MW are molecular weight standards whose size (in kD) are indicated at left.