Bacteriophages, viruses that selectively infect bacteria, are increasingly explored as potential therapies to combat antibiotic-resistant infections. Effective phage purification is vital for therapeutic use, particularly to reduce endotoxin (lipopolysaccharide, LPS) and host protein contamination from production processes in gram-negative bacterial lysates. This study investigates the purification efficiency of CIMmultus OH-monolithic chromatography for seven similarly sized tailed phages (Myoviridae and Siphoviridae families) infecting