From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Culture Fluid (培養液, Baiyōeki; Literally meaning "Cultivation Fluid") is an acid-like ooze.
Dragon Ball Z: Bio-Broly
Culture Fluid appeared in Dragon Ball Z: Bio-Broly. This ooze melted every living thing that got in its way, absorbing it into itself and increasing in mass. Its first victim was Jaguar's Dog, who foolishly jumped into it despite Jaguar's warnings. It also killed all of the Bio-Warriors, most of the scientific personnel, and Maloja, but only deformed the monstrous Bio-Broly.
After a very tedious fight against the mutated Super Saiyan clone, Trunks Brief thought back on all of the people who had been killed by Culture Fluid and decided to try and lure Bio-Broly underneath a tank containing Culture Fluid and then destroy it with a Ki Blast. The plan had a slightly delayed effect, and it only succeeded when Trunks was at Bio-Broly's mercy, but apparently killing Bio-Broly. In reality, Bio-Broly had merged with the Culture Fluid and the Culture Fluid had become far too powerful to contain. It seemed as if all hope was lost until Mister Satan inadvertently exposed the weakness of the Culture Fluid by diving into the ocean. Culture Fluid solidified into a rock-like substance when it came into contact with water. Son Goten, Trunks, and Krillin, with this newfound knowledge, exploited the weakness by firing a triple Kamehameha at the ocean to cause a tidal wave to cover the island and solidify any remaining trace of the Culture Fluid. Because of his having merged with the Culture Fluid, however, Bio-Broly resurfaced as a giant. Due to being drenched with the water, however, he solidified, allowing Trunks and Goten to destroy him and ending the clone's existence.