EA 65 reagent, Pap 3D reagent is an alcoholic solution of two acid dyes, Eosin Y and Light Green SF, with added phosphotungstic acid (PTA). The first step in using the Papanicolaou staining method implies nuclear staining with a hematoxylin solution, and next two steps consist of counterstaining using the monochromatic OG-6 or Orange II reagents and one of the polychromatic EA reagent formulations. The Orange G and Orange II molecules stain the cytoplasm, and in later stages of the procedure it remains only in the mature, keratinized cells. One of the polychromatic EA solutions is used in the third step. Those solutions diferentiate between squamous cells. Test samples can be gynecological and non-gynecological, such as sputum, urine, diarrhea, and cytological puncture samples. In order to obtain optimal staining results, EA 65 reagent, Pap 3D has properties completely in compliance with other BioGnost’s reagents for cytological smearing acc. to Papanicolaou – Hematoxylin HP reagent, Pap 1A or 1B, OG-6 reagent, Pap 2A, and Orange G II reagent, Pap 2B.