>Is there a good reason to run a negative control on every block when
>staining IHC's?  We do a lot of keratin stains on lymph nodes from the
>same specimen (not part A, part B, etc.) and we run a negative control
>along with the keratin on every block.
>
>Laurie Colbert

********

Speaking at least from research point of view:
Officially, every tissue block needs a negative control using a non-immune
reagent (normal rabbit serum, fake monoclonal antibody) replacing your
primary antibody. This non-immune control should be applied in the same
immunoglobulin concentration as the primary antibody.
See for example JHC 48:1431-1437, 2000 Table 1. Most immunohistochemical
journals do request for such non-immune negative controls.

Chris van der Loos
Amsterdam, The Netherlands