Adequate antibody clone – Antibody Lexicon

Use adequate antibody clone. Knowing the spectrum of the reactivity, staining pattern, crossreactivity and limitations of antibody clone you are planning to order is essential for proper interpretation.

A) Compare sensitivity of two different antibody clones against TTF-1 in endometrioid adenocarcinoma (with aberrant expression of TTF-1).

Fig. 5. Negative staining for TTF-1 in endometrioid adenocarcinoma metastatic to the liver (clone 8G7G3). 10x.

Fig. 6. Aberrant expression in endometrioid adenocarcinoma metastatic to the liver (clone SPT24). 10x.

B) Desmoplastic small round cell tumor (DSRCT) has a specific t(1;22)(p13;q12) translocation leading to the fusion of the Ewing sarcoma RNA binding protein 1 (EWSR1) and Wilms tumor suppressor (WT1) genes. The new fusion protein has N-terminal domain of EWSR1 protein and C-terminal domain of the WT1 protein. Consequently, the antibodies directed to the N-terminal of WT1 protein are not reactive in DSRCT, and only antibodies directed to C-terminal give expected positive nuclear staining in this tumor.

WT1. Negative staining of tumor cells with clone 6F-H6 (against N-terminal) in desmoplastic small round cell tumor (DSRCT). Positive cytoplasmic staining of endothelial cells is evident. Low magnification.

WT1. Positive nuclear staining of tumor cells with clone C-19 (against C-terminal) in desmoplastic small round cell tumor (DSRCT). No cytoplasmic staining of endothelial cells. Low magnification.

C) Insufficienty performing clone HM57 of anti-CD79a antibody demonstrates weak reactivity with neoplastic plasma cells and aberrant reactivity with unknown epitope on intestinal epithelial cells as compared with the performance of other anti CD79a antibodies, Reactivity of this clone with smooth muscle cells is also described.

CD79a clone HM57. Weak staining of neoplastic plasma cells in a case of myeloma as compared to much stronger staining of scattered non-neoplastic plasma cells.

CD79a clone HM57. Staining of normal plasma cells in lamina propria and aberrant staining of intestinal epithelial cells.

Back to Artefacts and pitfalls under staining and interpretation