Diagnostic information obtained from antibodies binding to random peptide sequences is now feasible using immunosignaturing, a recently developed microarray technology. The success of this technology is highly dependent upon the use of advanced algorithms to analyze the random sequence peptide arrays and to process variations in antibody profiles to discriminate between pathogens. This work presents the use of time–frequency signal processing methods for immunosignaturing. In particular, highly-localized waveforms and their parameters are used to uniquely map random peptide sequences and their properties in the time–frequency plane. Advanced time–frequency signal processing techniques are then applied for estimating antigenic determinants or epitope candidates for detecting and identifying potential pathogens.