Fig. 7. Halo assay for production of mating pheromone. Ten microliters of a cell suspension (∼1 × 10¹⁰ cells/ml) from strains RJY6012 (MATα Δnhp6a Δnhp6b), SEY6210 (MATα wt), DY2382 (MATa Δnhp6a Δnhp6b) and DY150 (MATa wt) were spotted onto a plate, grown overnight at 30°C and replica plated onto a lawn of 1–5 × 10⁷ cells of either MT503 (a-factor tester strain) or XP635-10C (α-factor tester strain) cells. Plates were then incubated at room temperature for 2–4 days.