Gram stain permits the separation of all bacteria into two large groups; those which retain the primary dye (gram-positive) and those that take the color of the counter stain (gram-negative). The primary dye is crystal violet and the secondary dye is usually safranin O, basic fuchsin or a combination of the two stains. Basic fuchsin improves anaerobe counter staining. There are many different formulations of crystal violet used. Catalog number 515K consists of Hucker’s crystal violet, stabilized Gram’s iodine, 25% acetone/alcohol and 0.4% Safranine O counterstain. The kit comes in two sizes, 8 oz. bottles or 16 oz. bottles. The country of origin is the United States.