There are many factors with which the chromatographer must concern himself to keep his LC columns functioning properly and for a long peroid of time. These involve solvent choice and/or cleanup, choice of salts and buffer makeup, care with cleanup, choice of salts and butter makeup, care with solvent gradients, temperature, pressure, and flow rates. Attention must also be paid to the column fittings, frits, and column configuration. Also important are correct sample makeup, stability, and injection. Certain protector columns can be built into the LC system. Finally, column reconditioning and repair are discussed along with the use of TLC to aid in selecting solvents for column cleaning.