EMS Technical Data Sheets

Section Block

EMS Catalog #62710, 62711, 62712


All antibody preparations have some potential to produce a non-specific reaction in the assay; it originates from:

All these are capable of non-specifically binding to molecules on tissue sections, blots, fixed cells and other objects for immune detection. In the case of retrieved formalin sections, the risk of non-specific reaction is increased, since the proteins comprising the tissue sections are denatured during HIER. This makes many domains accessible that are charged. They are also capable of binding the test immunoglobulins in a non-specific manner.

The standard means of blocking non-specific binding of specific antibody preparation is as follows: Add irrelevant protein, other serum, casein, etc. However, in most cases, many who have tried this found that increasing concentration of such blocking agent leads to a great reduction of specific reaction as well. This is a result of the lack of blocking molecules binding to access sites on section and thus sterically blocking the access to specific antibodies to epitopes of interest.

All of our buffers at Electron Microscopy Sciences are developed for immune assays and contain, instead, short (0.6-2 kD) peptides that are capable of block effectively to non-specific reactions. These do not affect the specific binding of antibody.


Section Block represents a new class of blocking solutions based on chemically modified and fragmented ultra-pure casein. Some of the advantages are:


Electron Microscopy Sciences recommends this product for research and diagnostic pathology, especially for HIER retrieved sections and polyclonal antibodies.

Use in IHC

  1. Apply to cryostat, or depaffinaized formalin-fixed, or processed in Retriever (or other epitope recovery device) tissue section quantity sufficient to cover the tissue (approximately 200 ml). Alternatively, incubate by submerging the sections into the buffer. Use Retriever Slide Chamber (Catalog #62705-01) to block many slides at once with minimal use of Block buffer.
  2. Incubate 30 minutes at room temperature.
  3. Rinse once with PBS or other suitable buffer, and proceed with immunostaining.

Note: For best results use Altibody Diluent (Catalog #62713) to prepare the solutions of primary and secondary antibodies.

Use in Other Applications

Section Block can also be used to prevent non-specific binding of reagents and to improve sensitivity in the following:

Block in similar manner for 30 minutes at room temperature.

Stability and Storage

Online Ordering

Section Block