For the cultivation of Haemophilus, Levinthal’s Medium can be used. Although there are many species in the genus Haemophilus that can cause infections, they all share a common morphology. They also require blood-derived factors for growth. This is what gave the genus its name. The Haemophilus Genus is a large grouping of gram-negative rods, which can grow on agar-containing human blood. Two factors are required for Haemophilus species to grow: factor-X, and factor-V.