The cytological staining technique developed by Papanicolaou is still the standard method in cancer and hormone cycle diagnosis. The modified hematoxylin solution S (Papanicolaou’s solution 1b) provides good nuclear staining in 2-3 minutes. Nuclei are stained blue, dark violet to black. A 500 ml bottle is sufficient for 1500 up to 2500 slides. It is registered as IVD and CE certified product and can be used for clinical diagnostics.