**Abstract**

In Vitro culture is a technique commonly used for plant research. Nevertheless, it is more expensive than traditional methods of production, due to the use of the culture medium gelling agent called agar. Recent studies have been searching for alternative substances in raw materials with the same characteristics but which can be extracted easier than agar. The dietary fiber of the nopal cactus (Opuntia) is a rich source of hydrocolloids (pectin and mucilage). These hydrocolloids have the ability to gel in combination with the indicated solution. In this chapter, we will focus on the study of the hydrocolloids from nopal cactus to replace agar partially and/or totally as a gelling agent using in vitro culture media benefiting from the molecular structure and mechanical properties of the compounds.

**Keywords:** In vitro culture media, gelling agents, mechanical properties, molecular structure, nopal cactus hydrocolloids
