​Chemicals

    Pyronin Y is a cationic dye, that intercalates RNA to form fluoresent complexes, enabling quantitative analysis of cellular RNA. One of the most notable applications of Pyronin Y is in the differential staining of RNA and DNA, where it is often used in conjunction with methyl green or with Hoechst 33342, known as the green-Pyronin or Hoechst 33342-Pyronin  co-staining.  In the green-Pyronin staining, the RNA stains red with Pyronin, and DNA, which takes up the green stain with methyl green. Furthemore, in the Hoechst 33342- Pyronin staining, the presence of  fluorescent DNA-Hoechst 33342 complexes interupts the interactions of Pyronin Y and DNA, results in the majority of staining between Pyronin Y and RNA. Therefore, allows the quantification of RNA amount in cells. Generally, resting/quiescent cells at G0 phase have lower levels of RNA compared with proliferating interphase cells (G1-S-G2-M phase). The Hoechst 33342- Pyronin staining is useful method to identify the resting cells (G0 cells) from proliferating cell.