Category C - full version without watermark 720x576 (check terms and conditions at www.teledesign.de) The version with watermark is for free to embed - Text: Tumor tissue cells change their structure. A tumor cell eliminates all genes that might stop it from growing expansively and activates all genes that are required for growth. Within the single cells the ratio of genetic material and mRNA hence changes. A fact that is used for DNA-chip technology. On the chip surface short DNA sequences are attached that are known to be normally present or transcribed in breast tissue. They are called DNA probes and work like a fishing-rod. One chip can carry up to 100.000 probes Now healthy as well as tumor tissue samples are collected. From those DNA or mRNA is isolated and fluorescence labeled. If a droplet of this solution is brought onto the chip the DNA probes will bind to the complementary DNA and mRNA strands respectively.