Production of biological drugs involves multiple steps of isolation and purification of the target drug substance (biomolecule). Most commonly used technique for isolation and purification is chromatography of which chromatographic columns are the vital part. After each industrial process, regeneration and cleaning of chromatographic columns are crucial to prevent carry-over of the product from one batch to another. The aim of this diploma thesis was therefore to test the efficiency of regeneration and cleaning of chromatographic columns that are used in production of target biomolecule. For this purpose a blank elution (without previously loading the protein) was executed after a routine process. The chromatogram of blank elution was compared to the master chromatogram, which showed no signal of absorbance. In addition, the content of the drug substance in blank eluate was analysed. Results obtained in this study confirmed the hypothesis, that regeneration and cleaning of chromatographic columns involved in drug substance production are effective. The study was performed at all chromatographic steps in drug substance production with the exception of the size exclusion chromatography, where there is no interaction of product with chromatographic resin.