Microarray sampling-platform fabrication using bubble-jet technology for abiochip system

The fabrication of microarrays containing PCR-amplified genomic DNA extract s from mice tumors on a Zetaprobe membrane using a modified thermal ink-jet printer is described. A simple and cost-effective procedure for the fabric ation of microarrays containing biological samples using a modified bubble- jet printing system is presented. Because of their mass-produced design, in kjet printers are a much cheaper alternative to conventional spotting techn iques. The usefulness of the biochip microarray platform is illustrated by the detection of human fragile histidine triad (FHIT), a tumor suppressor g ene. Subcutaneous carcinomas were induced with MKN/FHIT and MKN/E4 cell lin es in immunodeficient mice. Several weeks into their development, the tumor s from both groups of mice were removed and subjected to DNA extraction by lysis of tissue samples. The extracted DNA samples were amplified by PCR (3 0 cycles) using the primers corresponding to nucleotides 2 to 18 of the FHI T sequence. The resulting solution was transferred to the individual reserv oirs of a three-color cartridge from a conventional thermal ink-jet printer (HP 694C), and arrays were printed on to a Zetaprobe membrane. After spott ing, these membranes were used in a hybridization assay, using fluorescent probes, and detected with a biochip.