Start with ethically-sourced peripheral blood (PB) products from donors diagnosed with ulcerative colitis (UC), including frozen MNCs or PBMCs, plasma and custom products.Leukopaks are enriched leukapheresis products consisting of a large number of single-donor MNCs, collected using the Spectra Optia Apheresis System, with acid-citrate-dextrose solution A (ACDA) as anticoagulant. Primary human MNCs are isolated from PB leukapheresis samples using density gradient separation or RBC lysis, cryopreserved in CryoStor CS10 (Catalog #07930). All products are obtained from donors with UC, confirmed by collection facility Medical Director, using Institutional Review Board (IRB)-approved consent forms and protocols. Additional documents, specifications, disease and treatment information, and high-resolution HLA typing (Class I and II alleles) may be available upon request. Donors are screened for HIV-1, HIV-2, hepatitis B and C.Certain products are only available in select territories.