Vector Laboratories
ImmEdge Pen
H-4000
Our lab tried several pap pens after several failed Dako pens. The ImmEdge was the best performer, but does retail at $300 each! It dried quickly and has a shade of blue, so it's easy to see as you apply it to the slide. Was smudge proof after drying, you could run your latex glove over it and it remained in place. Sigma Liquid Blocker also performed well at a cheaper $125 each but went on clear and a little hard to see. Dako was an epic fail as well as EMS super pap pen from Pro Sci Tech Cat#EMS71310; runny and took forever to dry and did not remain in place.
Slide Mounted Immunohistochemistry
PBS washing and triton X block with serum, antibodies etc
None
Worked well and stayed on
N/A
Dried quickly and remained in place
The price is expensive
Best product but expensive. Sigma equally as good but harder to see.