slides to be stained for
CD79a contained four small lymphocytic
lymphomas/chronic lymphatic leukaemias
(specimens 1-4), a normal
5), a colon carcinoma
(specimen 6), three Hodgkin
lymphomas LP (specimens
7-9), and three follicular lymphomas
laboratories submitted stainings. 48 used
mAb clone JCB117 (DakoCytomation), three used
clone HM57 (DakoCytomation)
and one used
HM47/A9 from Novocastra. All
At the assessment, 27
laboratories (52%) achieved optimal staining, 16 (31%) acceptable, 8 (15%) borderline, and 1 (2%) poor staining.
Mandatory for an optimal CD79a staining reaction was the use of
mAb JCB117 appropriately diluted in combination with an efficient HIER protocol.
The most frequent reasons
for an insufficient staining were:
dilute primary Ab concentration (particularly
when a less sensitive protocol was used)
- use of
mAb HM57 (weaker B-cell staining, cross reaction to epithelia and
smooth muscle cells).
tissue, normal lymphatic tissue is suitable. A strong staining of almost all germinal centre cells should be seen.