Staining solution reagent Gram

for histologyfor cytology

Minimum number of tests that can be performed 100 Completion time 40 minutes Shelf life 2 years Storage conditions 15-25°C Additional equipment 3 vertical glass histology jars, funnel, filter, oven Application Method for differentiating Gram-positive and Gram-negative bacteria on histological sections, smears and tissue apposition. Result Gram-positive bacteria blue Gram-negative bacteria red Nuclei red Product for the preparation of cyto-histological samples for optical microscopy. To differentiate between Gram-positive and Gram-negative bacteria in tissue sections. PRINCIPLE Gram staining is the most important method to differentiate bacteria species. Two dyes are used one after the other: crystal violet and fuchsine. Crystal violet solution precipitates through oxidation with a iodine solution. The deriving complex attaches to bacteria cell walls with bonds of varying nature and intensity. The differentiating solution removes the crystal violet-iodine complex from the walls of some bacteria, but it does not act on others. These retain the primary dye and are called Gram- positive. Decolorized bacteria are then counterstained with a red dye; they are called Gram-negative. Gram-positive bacteria’s capacity to retain the dye-iodine complex is usually ascribed to the bond which develops between the complex and a molecule only Gram-positive possess, namely magnesium ribonucleate