Yes. When virus stocks are not yet available, the project can be initiated from rescue-ready plasmids or design concepts, depending on the viral system, genome design, and biosafety review. In this situation, the first stage usually focuses on confirming feasibility, clarifying the rescue or construction route, and defining what material quality will be required before comparative screening. Additional virus construction, rescue, amplification, identity confirmation, or titer determination may be recommended before the candidate set enters side-by-side testing.

The number can range from a few closely related variants to a broader comparison across different viral backbones or engineering designs. The recommended scale depends on assay complexity, available material, model number, endpoint depth, and whether the project requires primary cells, 3D systems, or immune co-culture assays. For larger candidate sets, Creative Biolabs can structure the program as a staged screen, using an initial rapid triage step to narrow the list before deeper replication, selectivity, immune-response, or developability testing.

Yes. 3D tumor spheroids, organoid-like models, or other tumor-architecture systems can be incorporated when the program needs a more stringent evaluation of viral spread, penetration, replication behavior, and killing under tissue-like conditions. These models are often used after an initial 2D screen narrows the candidate list, because they typically require more optimization and material. They can be especially useful when a candidate shows strong activity in standard cell culture but the project needs additional evidence for tumor penetration, multicellular resistance, or model-dependent performance.

The service can include both experimental data and an integrated candidate recommendation report, depending on the requested scope. The recommendation can combine potency, selectivity, replication kinetics, immune-response signals, normal-cell safety observations, and developability considerations into a comparative ranking framework. The report may also discuss assay limitations, data confidence, candidate-specific risks, and suggested next-step experiments, so the output is useful for lead selection rather than only a collection of raw results.

Yes. Candidate screening can be designed to generate the rationale for downstream in vivo work, including animal model selection, dose range planning, route of administration, pharmacodynamic endpoints, efficacy readouts, or biodistribution follow-up studies. For example, in vitro infectivity, replication, and selectivity data can help identify which tumor model and dosing assumptions are most appropriate before animal resources are committed. The final screening report can therefore serve as a bridge between early candidate comparison and a more focused preclinical validation plan.