Cacodylate buffer with a pH of 7.4 and a concentration of 0.1 mol/l is a frequently used buffer in biology and biochemistry. It consists of sodium cacodylate, a salt of cacodylic acid, which itself is derived from arsenic acid. Because of its buffering capacity, cacodylate buffer is used to maintain a constant pH in biological samples and reactions.

The use of cacodylate buffer is widespread in histology, cytology and electron microscopy. It provides effective fixation and stabilization of sample structures, facilitating subsequent examination and analysis. Cacodylate buffer can also be used in combination with other fixatives, such as osmium tetroxide or glutaraldehyde, to achieve improved preservation of sample structures.

Although cacodylate buffer is effective and widely used, it should be noted that it is toxic and environmentally harmful because it is based on arsenic compounds. Therefore, care should be taken when working with cacodylate buffer to avoid exposure to its toxic properties. Alternatively, less toxic buffers, such as HEPES or MOPS, can be used if they are suitable for the specific application.