Safety pins were also used for serum therapy to facilitate the practitioner's work and make it less tiring: "the ampoule is held at a certain height after it has been punctured and the liquid seeps under its own weight, emptying the ampoule, which usually comes with a wire, frame or tape to fasten it the support with safety pins or bandage, thereby avoiding the tiring task of holding the ampoule up" BC8:619.
También el imperdible se podía usar en procedimientos de sueroterapia para hacer más cómodo y menos cansado el trabajo del profesional: "se sujeta la ampolla a cierta altura una vez que se ha pinchado, y el liquido penetra por su propio peso, vaciándose la ampolla.