“What is a PAP-Pen?”
As a simple product used in the field of biology and histology, PAP Pen comes in a wide range of names:
- PAP pen – is the most common
- Hydrophobic pen
- Hydrophobic barrier
- water repellant pen
- blocking pen
- liquic blocker
- Blocker pen
- Pen for IHC
- Immunostaining blocker
And many more – You got the point.
The idea is very simple: Take a small piece of tissue and cut it using a cryotome or microtome to slices between 4-60 micron (0.004-0.06mm or 0.00015-0.0012″). The thickness will vary depending on your needs and experimental plans. Cryotome sections are performed on frozen samples and are left to dry off overnight before storage or performing immunohistochemistry (IHC) or immunoflourescense (IF). Microtome slices have to be prepared using xylene and paraffin is replacing the original place of water in the tissue, thus holding everything solid to be cut.
Now you start your process – IHC or IF, but to mark your proteins of choice inside or on the cells you need to use antibodies. Antibodies are expensive! This is how to do it right:
How do we prevent them from spilling off the glass? We use a hydrophobic barrier to make a line round our work (shown below is a BarrierPaste line).
Preferably you would like to differentiate between your samples, antibodies or controls. Hence, the use of color-coding using different pens is recommended.
Once you have made this barrier around your sample you can use a very tiny amount of antibodies, fixatives, detergents and other reagents to check your tissue.
What is it good for, you ask?
IHC and IF are both used for many things, starting with cancer diagnosis, disease idnetification, pathogen detection in tissues and basically, in many biological reasearch projects in almost any field.
Hope this helps,
Regards,
Invignome Team