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ImmEdge® Hydrophobic Barrier PAP Pen (H-4000)



The ImmEdge pen (H-4000) is an improvement over the PAP pen for tissue specimen preparation. Its hydrophobic barrier feature provides a stable, water-repellent barrier that keeps reagents localized on tissue specimens, preventing reagent mixing when multiple sections are mounted on the same slide.

The barrel of the ImmEdge Pen is composed of acetal plastic which allows for consistent tip retention, easier tip saturation, and improved fluid flow.

ImmEdge Hydrophobic PAP Barrier Pen Features:

  • Stable for use with buffers with and without detergent (Tween 20, Triton X-100, etc.)
  • Light blue barrier compatible with enzyme or fluorescence-based detection systems
  • Soluble in all commonly used clearing agents
  • Environmentally friendly – does not contain “ozone-depleting” substances as identified by the Montreal Protocol or the Council of the European Union


Unit Size2 pens
ApplicationsImmunohistochemistry / Immunocytochemistry, Immunofluorescence, In situ hybridization
Safety TitleWARNING: Cancer and Reproductive Harm –

Product FAQs

The volume of the ImmEdge Pen (H-4000) is about 6 mL. We have not characterized how many times it can be used or overall length of the barrier due to variability in its application.

The nib provided with each ImmEdge Pen is 3 mm wide.

Yes. The ImmEdge Pen residue contains a wax constituent that allows for application to microscope slides that have buffer or similar aqueous solutions on the surface. Applying the pen residue to wet slides does not affect adhesion of the residue nor interfere with the tissue section.

Yes, the pen residue does fluoresce. However, this property does not limit the pens use to only light microscope applications. We routinely use the ImmEdge pen for immunofluorescent tissue staining applications. Usually the pen residue is applied well outside of the tissue section perimeter, and as such, the inherent fluorescent properties of the pen residue do not interfere with specific fluorescent signal.

Yes. The pen design ensures the nib can move and that the nib is not adhered to the pen itself. The nib needs to move so that once received the nib can be depressed to break the internal membrane to allow residue to flood the nib. In some instances, during shipping, the nib may become dislodged and fall out. Simply put the nib back into the neck of the pen and use as per the supplied instructions. Once the residue floods the nib, the nib material expands slightly to hold the nib within the pen neck.

The pen residue does contain a solvent that dries within seconds of being placed onto the slide. There is no requirement to wait for the residue to dry. In essence the residue dries the moment it is applied.


Technical Information

The ImmEdge Pen barrier is stable for use with buffers with and without detergent (e.g. Tween 20 or Triton X-100, etc.). The pale blue barrier is insoluble in alcohol and acetone, but is completely removed by all commonly used xylene and xylene substitute clearing agents. The barrel of the ImmEdge Pen is composed of acetal plastic which allows for consistent tip retention, easier tip saturation, and improved fluid flow. Check out the video below on how to use a hydrophobic barrier pen.


Applicable patents and legal notices are available at legal notices.

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