I am trying to test an assay setup that requires a relatively large piece of skin sample (2-3 inches in diameter). Can someone suggest a substitute material that has similar consistency and is easy to obtain and cheap?
I don't know if this qualifies as a "skin substitute" but potato skin/thin peels are actually *used* as a skin substitute in burn patients - you can look that up to see if the peels are treated in any way.
Richard is correct- pig skin is widely considered the best model tissue for human skin in the wound care field.
Sullivan TP et al (2001). The pig as a model for for human wound healing. Wound Repair Regeneration 9(2):66-76
Middelkoop E et al (2004). Porcine wound models for skin substitution and burn treatment. Biomaterials 25(9):1559-67.
If you just need an anatomical / mechanical model, you can purchase a pig belly from your local abattoir. The dermal and epidermal layers will be approximately the same as in human skin (~2-2.5mm), the thick layer of fat can be dissected away.
If you need a living construct, try Apligraf from Organogenesis (http://www.apligraf.com/). It's expensive, though. I asked a rep at a meeting about the possibility of obtaining some expired samples for my in vitro work, but never heard back.