Immunohistochemical analysis of tumor biopsies with autologous serum. Immunohistochemical analysis of NHL specimens, with a homogeneous population of small lymphoid cells from a complete (A,B), a partial (C,D), and a nonresponding patient (A-F), immunostained with biotin-conjugated autologous prevaccination (A,C,E) and postvaccination (B,D,F) serum samples at the indicated serum dilutions. Lymphoid neoplastic cell-restricted autoreactivity was evidenced only when the postvaccination sera of the complete (B) and the partial (D) responders were used. No tumor-restricted immunostaining was detected either in prevaccination (E) or postvaccination (F) serum samples of a nonresponding patient. Nonneoplastic follicular DCs and endothelial cells present in the inset of panels A, B, and E showed no immunostaining (). Panel insets are shown at ×40 original magnification; panels, at ×10 original magnification. Images were acquired using Leica DMD108 (Heidelberg, Germany) equipped with HI Plan 10×/0.25 and 40×/0.65 objectives and processed in Adobe Photoshop CS3 software (San Jose, CA).