This system utilizes the interaction of the repressor (lacI) and the operator (lacO). control over the ratio between biologic drugs produced together; (ii) consolidated bioprocessing; and (iii) co-expression and co-purification of a mixture of two monoclonal antibodies. We then use these basic strategies to produce drug mixtures as well as to separate drugs. These strategies offer a diverse array of options for on-demand, flexible, low-cost, and decentralized biomanufacturing applications without the need for specialized equipment. The ability to combine the production of multiple biologics into a single on demand system could help in situations where resources are limited. Here the authors demonstrate a proof-of-concept approach for the co-production of three biologics, allowing singular, mixed and combination drug products. Introduction The shortage of essential drugs is usually of global concern1,2, especially in developing countries. In underdeveloped countries, BCL2 governments may face budget limitations that prevent infrastructure improvement. Even in developed countries, emergency situations can compromise the supply of important medicines, such as the insulin shortage crisis in New Orleans after Hurricane Katrina3, or raise the risk of infectious disease outbreaks that need to be rapidly addressed. On-site, small-scale drug manufacturing can provide drugs on demand for isolated or inaccessible regions4C6. However, it is difficult to precisely predict the types and amounts of drugs needed in a certain region and time, so a large number of strains have to be cultivated and multiple facilities built in order to generate a Golotimod (SCV-07) large Golotimod (SCV-07) supply of needed drugs. Golotimod (SCV-07) High capital investment and maintenance costs and low utilization rates make such production difficult in regions with limited resources. Therefore, it would be of great interest to have a versatile platform to manufacture a variety of different drugs on demand and on site with low capital investment. Biologics manufacturing involves four phases: strain/cell line construction, upstream processing (fermentation), downstream purification, and drug formulation. Usually, each biologic is usually produced in one strain within a manufacturing facility. Although economically efficient for large-scale production in biopharmaceutical plants, this method is usually inefficient and time-consuming for small-scale production, which would be useful for single-dose production, laboratory-scale research, and clinical studies7,8, in addition to the conditions mentioned above. We envision that performing multiple bioprocesses simultaneously can overcome challenges in portable and/or small-scale biologics manufacturing. Here we sought to co-produce multiple drugs in a single batch via a versatile platform (Fig.?1) that: (i) generates several drugs on demand rather than one by one; (ii) enables control over the ratio of co-produced drugs and reduces the overall manufacturing time; and (iii) separates and purifies drugs in a two-stage downstream process to efficiently recover products and eliminate cross-contamination. This co-production strategy can also be used to manufacture combination drugs, i.e., drugs containing two or more active pharmaceutical ingredients. Combination drugs can have synergistic effects on a single disease or confer broad protection9. For example, cocktails consisting of multiple antiretroviral drugs are widely used against HIV10, and combination vaccines allow for fewer administrations but broad-spectrum protection against several pathogens11. Another class of combination drugs consists of polyclonal antibodies, which are mixtures of synergistic monoclonal antibodies (mAbs) that simultaneously interact with multiple epitopes either on the same target or on distinct targets12C15. For example, ZMapp, an anti-Ebola computer virus drug, combines three mAbs16; another example is the combination of lumiliximab and rituximab, which has shown enhanced antitumor effects in clinical studies17. Although mAb mixtures have certain advantages, such as synergistic effects and broad-spectrum protection18C21, the cost to manufacture them using conventional strategies is much higher than that of producing single mAbs because Golotimod (SCV-07) each mAb needs its own.