The SPOT technique provides a fast, cost-efficient, and highly parallel method to synthesize peptide arrays on cellulose. Peptides synthesized on cellulose can be easily cleaved from the support and used directly in a screening assay for antimicrobial activity. Depending on the equipment, the synthesis and the screening can be performed in a medium- or high-throughput manner. High-sensitivity screening is achieved using a bacterial strain (e.g., Pseudomonas aeruginosa H1001) in which a luminescence-encoding gene cassette has been introduced. The intensity of light produced is directly dependent on the energy level of the bacteria. This screening supports the development of new drugs against multidrug-resistant bacteria.