Case Based Reasoning has been applied in different fields such as medicine, industry, tutoring systems and others, but in the CBR there are many areas to explore. Nowadays, some research works in Bioinformatics are attempting to use CBR like a tool for classifying DNA genes. Specially the microarrays have been applied increasingly to improve medical decision-making, and to the diagnosis of different diseases like cancer. This research work analyzes the Microarrays structure, and the initial concepts to understand how DNA structure is studied in the Bioinformatics' field. In last years the CBR has been related to Bioinformatics and Microarrays. In this report, our interest is to find out how the Microarrays technique could help in the CBR field, and specially in the Case-Based Maintenance policies.