CTL has long been recognized as the leader in peer-reviewed scientific publications on ELISPOT assays, instrumentation, and software, as well as their clinical applications. In recent years, CTL has expanded its portfolio to include instrumentation for bacterial, yeast, stem cell, and tumor colony counting, as well as for analyzing various plaque and clonogenic assays. Also offered are reagent solutions such as cryopreserved PBMC, CEF peptide pools, and serum-free media. CTL products include: • ELISPOT analyzers • Plaque and colony counters • Cryopreserved PBMC samples • Serum-free cell culture media • CEF peptide pools • Image analysis software