Antiviral Services

RetroVirox is the only CRO specialized in proving antiviral services to Pharmaceutical and Biotechnology companies worldwide. Antiviral services offered at RetroVirox include a full menu of in vitro antiviral assays against many important human pathogens including coronaviruses, HRSV, HIV, influenza, DENV, ZIKA, HRV, HCMV, HSV, LCMV, and hepatitis viruses.  The company has also a battery of viral pseudoviruses carrying heterologous envelope proteins. HIV pseudoviruses are used in surrogate assays to determine (under BSL2 conditions) the neutralizing activities of mAbs and antisera against a variety of highly pathogenic viruses, including SARS-CoV-2 (nCoV-2019), MERS-CoV, SARS-CoV, Lassa fever virus, Ebola and avian influenza (H5N1). RetroVirox can also evaluate antisera to determine whether they display neutralizing activity against some of the most common gene therapy vectors, including adeno-associated virus vectors (AAV)

Unlike other Contract Research Organizations (CRO), RetroVirox is specialized in offering biological services exclusively in the antiviral field. We work with virtual start-up companies lacking the appropriate facilities to perform antiviral studies, and with large Biotechnology and Pharmaceutical companies seeking CROs with unique expertise in the virology field. RetroVirox master agreements are 100% “IP friendly” RetroVirox does not take any ownership nor intellectual property rights over any studies or compounds evaluated for other Life Sciences companies. Customers own the intellectual property of all data generated in our services.

As experts in the antiviral field, we provide a vast menu of antiviral services to evaluate the inhibitory activity of prospective inhibitors. We also offer a number of tailored antiviral assays to address the mechanism of action of novel antivirals. Development and optimization of new antiviral assays against other viruses is always under progress. We encourage you to contact us and inquire about any antiviral needs you may have. Cytoxicity assays in transformed cells or primary cells is available with all antiviral studies to determine CC50 values and selectivity indices when possible.

RetroVirox also offers several multi-viral and multi-strain panels to assess the specificity of antivirals and mAbs, and to help identify and evaluate items with broad-spectrum antivirals activities (read more). With one of the largest collections of viral strains available (over 200 viral strains of 18 different viral species) RetroVirox can evaluate your molecules for activity against most commercially important human viruses.

To request information or quotes call us at (858) 232-7919 or contact us at

Additional information about specific antiviral assays offered against several human viruses click on the following links:



Influenza viruses

Influenza Panel (20 strains)

Human Respiratory Syncytial Virus (HRSV)

Dengue (DENV) and ZIKA (ZIKV)


Human Cytomegalovirus (HCMV)

Human Rhinovirus (HRV)

Highly Pathogenic Viruses (SARS-CoV-2, MERS, SARS, EBOV, Lassa, Avian Influenza)

HIV Pseudoviruses for Neutralization Assays

AAV Neutralization Assays

Multi-virus panel

HTS Campaigns with Live Virus

Consultancy Services

To request information or ask for a quote call us at (858) 232-7919 or contact us at

Selected Assays Performed at RetroVirox

  1. Infectivity and replication assays

  2. High Throughput Screening (HTS) against viral targets (45,000 small-molecule library available for pilot studies)

  3. Microneutralization assays

  4. In vitro evaluation of vaccine responses

  5. Plaque reduction assays (PRA)

  6. Virus yield reduction assays

  7. In vitro drug-resistance virus selection

  8. Cross-resistance analyses

  9. Phenotypic characterization of clinical samples (HIV, HRSV, and influenza)

  10. Hemagglutination assays (HA)

  11. Enzymatic assays (viral neuraminidase and viral protease)

  12. Viral replicon assays

  13. Customized virus production (infectious or inactivated)

  14. Combination therapy studies (in vitro)

  15. CPE-based antiviral assays (TCID50)

  16. Mechanism of action studies

  17. Target identification by reverse genetics

  18. Virus stability assessment (virucides and stabilizers)

  19. Comparison of experimental diagnostic tests with commercial assays

  20. In vitro evaluation of microbicides

Mechanisms to Access Antiviral Services

RetroVirox offers its services in two modalities to accommodate the need of the smallest and largest companies:



This is the most common mechanism used for CROs. To request a quote email to or call us at (858) 232-7919


Grant Collaborations

This type of service is not provided by standard CROs. In this mechanism, RetroVirox works as a  “collaborative research organization” rather than a contract research organization. RetroVirox establishes collaborations with companies seeking funds from federal agencies and works with these companies to help them secure financing and meet their R&D antiviral needs.

RetroVirox offers these collaborative opportunities to small start-up companies and mid-size Biotechs with promising therapeutic projects. Our staff will provide FREE guidance in all aspects of the grant application, including the identification of appropriate sources of financing, contacting NIH officers, designing research and business strategies for the proposal, preparing budgets and helping throughout the entire submission process. RetroVirox and its staff have a great deal of expertise in securing awards from multiple sources, including the National Institutes of Health (NIH). Our staff has prepared SBIR (R43, R44), STTR (R41-R42), RO1s, R21s and other NIH grant applications.


To inquire about collaborative opportunities to apply for federal grants please email to or call us at (858) 232-7919

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