Abstract: Optical fingerprints for label-free high-throughput (epi)genomics, transcriptomics, and proteomics profiling of single cells. Vibrational spectroscopy signatures combined with a molecular identification algorithm rooted in machine learning enables identification of nucleic acids and amino acids, and their molecular variations, thereby identifying genetic variation by mapping heterogeneity and identifying low copy-number variants. Additional embodiments include the BOCS algorithm which takes measurements of DNA k-mer content from high-throughput single-molecule Raman spectroscopy measurements and maps them to gene databases for probabilistic determination of genetic biomarkers at low coverages. Starting with a log of measured k-mer content blocks (B1 . . . Bn as shown) and a genetic biomarker database (excerpts from the MEGARes antibiotic resistance database are shown), the blocks are individually aligned to each gene in the database based on content.