Safranin O Protocols

Safranin O is a chemical substance used in molecular biology as a stain or dye. This colorant reacts with cartilage, which is the tissue forming ears, nose and joints; bacterial endospores, immunodefense response substances called granules and some proteins such as mucins. Safranin O protocols include cartilage staining, endospore staining and decalcified condyle.

Cartilage-Staining Protocol

• This protocol is used for the detection of cartilage; mucins, a type of heavy-weight protein produced in the skin tissues; and immunodefense mast cell granules, made of heparin and histamine. Cartilage samples are treated with formalin and paraffin, reports IHC World. Technicians hydrate the samples with water, stain with Weigert's iron hematoxylin and wash it off. Then they stain the samples with fast green colorant and rinse with acetic acid. They add 0.1 percent safranin O solution. After five minutes, the samples are dehydrated with ethyl alcohol. Microscope observation shows nuclei in black and cytoplasm in gray-green. Cartilage, mucin and mast cell granules are orange to red.

Endospore-Stain Protocol

• Endospores are structures formed within dormant or vegetative bacteria cells that serve as a mechanism of survival when the organisms are under stress. According to the American Society for Microbiology, safranin can be used in conjunction with malachite green dye in the study of these vegetative cells. Under microscope observation, the endospores are green, while the vegetative cells are brownish-red or pink. Proceedings include heat fixation of samples on slides, malachite green staining under a heat source, water-washing the samples and staining with safranin O in an alcoholic solution.

Decalcified-Condyle Protocol

• This protocol is used in the laboratory study of decalcification of joints or condyles. According to Yuehuei An in "Handbook of Histology Methods for Bone and Cartilage," safranin O in an aqueous solution is used to stain cartilage and calcium-lacking areas. Technicians stain rabbit condyle slides with safranin O for 40 minutes, rinse in three charges of distilled water and dip the samples in an alcoholic solution of fast green for 30 seconds, followed by a quick dip in acetic acid. They rinse the samples with water and dehydrate them with ethanol alcohol. A substance called xylene is added prior to microscope observation.