Acute respiratory infections (ARI) are a significant cause of high morbidity in both developing and industrialized countries. The wide range of pathogens and the strong overlap of the diseases they cause complicate diagnostics. Common laboratory diagnostic methods are often labor-intensive and costly, and may not be available for all pathogens. For this reason, a DNA microarray should be developed that allows for the simultaneous detection of up to 19 viral and bacterial pathogens in nasopharyngeal secretions from infected patients. To create the microarrays, pathogen-specific PCR products (126-463 bp) and oligonucleotides (17-30 nt) were spotted onto epoxy-coated glass slides. The PCR products were previously amplified and purified. The sequences of the probes were derived from a validated reverse transcriptase multiplex PCR-ELISA detection method, which was developed for the detection of 19 pathogens. To establish the method, hybridizations were performed with nucleic acids from cell culture supernatants and with nucleic acids from patient samples.