After obtaining his degree in biochemistry, Popov served as a division head at the State Research Center of Virology and Biotechnology (known as "Vector") and at Obolensk, both branches of the Soviet bio-weapons program dedicated to developing genetically enhanced products.
His work included "designer" bio-agents that would cause the symptoms of lupus and rheumatoid arthritis, in which a victim's auto-immune system attacks its own body.
By splicing myelin into Legionella (Legionnaires' disease), they also created an agent that caused brain damage, paralysis and death.
At Oblensk, Popov and his team spliced the diphtheria toxin gene into the plague bacterium, thus creating a highly virulent and deadly strain.
Popov has described Biopreparat's "Project Bonfire", whose goal was to develop antibiotic-resistant microbial strains, and "Project Factor", whose goal was to create microbial weapons with new biologic properties that would result in high virulence, improved stability, and new clinical syndromes.