“Andraka cultured MIA PaCa cells, from a commercial pancreatic carcinoma cell line, which overexpress mesothelin, a biomarker for pancreatic cancer. The mesothelin was isolated, concentrated and quantified with ELISA.^[6] After optimization with the Western Blot assay, the human mesothelin-specific antibodies were mixed with single walled carbon nanotubes and used to coat strips of ordinary filter paper. This made the paper conductive. The optimal layering was determined using a scanning electron microscope. Cell media spiked with varying amounts of mesothelin was then tested against to the paper biosensor and any change in the electrical potential of the sensor strip (due to the changing conductivity of the nanotubes) was measured, before and after each application. ”