Figure 2.
The salt extract fraction contains lyn and stimulated BCR but not syk, CD22, or CD45. Spleen cells from anti-HEL BCR transgenic mice were stimulated and separated as in Fig. 1 and probed with a mixture of anti-Igα, anti-Igβ, and anti-lyn or with anti-syk, anti-CD22, or anti-CD45. Three times as many cell equivalents were loaded in the salt extract fraction lanes as in the soluble fraction lanes. The CD45 blot is from a different experiment than the other blots, but BCR partitioning was similar in that experiment. 125I quantitation shows >300-fold enrichment of CD45 in the soluble fraction.