Hank's Balanced Salt Solution (HBSS), without calcium chloride, magnesium chloride, and with phenol red, is widely used in cell culture and biological research. It serves as a physiological buffer to maintain optimal pH and osmotic balance for cells during experiments. Its formulation without calcium and magnesium makes it suitable for applications where these ions could interfere, such as in cell dissociation or enzyme studies. The inclusion of phenol red allows for easy visual monitoring of pH changes, ensuring the environment remains stable. HBSS is commonly employed in cell washing, sample preparation, and as a diluent for reagents. It is also used in flow cytometry, immunoassays, and other procedures requiring a balanced ionic environment.