Figure 3.

TNP–Ficoll response depends on Btk dosage. Eight- to 12-week-old xid, xid^1xtg, xid^2xtg, and wild-type (wt) mice were immunized with 10 μg TNP–Ficoll and bled 6 days later. Serum was diluted 1:100, 1:400, and 1:1,600. Anti-TNP IgM was measured by ELISA. OD₄₀₅ readings are presented as mean ± SD. The number of individual mice tested in each group is as follows: xid, 8; xid^1xtg, 8; xid^2xtg, 8; wt, 5. All results differed significantly from each other (P < 0.001).