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 607K-SI consists of Gram’s crystal violet (catalog # 512A-8OZ), stabilized Gram’s iodine (catalog # 605A-8OZ), 25% acetone/alcohol (catalog # 304A) and 0.4% Safranine O counterstain (Catalog # 7964A-9OZ). The country of origin is the United States.