1% Toluidene Blue in 1% Borax

This ready-made stain (T047 100ml) is used for TEM semi-thin sections. Toluidine blue is a basic thiazine metachromatic dye with high affinity for acidic tissue components such as those rich in DNA and RNA. It stains nucleic acids blue and polysaccharides purple. The stained sections can be used in the light microscope to determine the area of interest and therefore quickly identify any necessary further trimming of blocks for ultrathin sectioning. The 1% borax reduces staining time whilst maintaining quality. The stain also increases the sharpness of histology slide images. In plant sections it can help distinguish between phloem and xylem cells.