¹Department of Analytical Chemistry, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey DOI : 10.35333/jrp.2020.206 The objective of this study was to investigate if UPLC/MS system without chip or Jetstream technology could be used in proteomics. A regular UPLC column (2.1 mm × 150 mm, 1.7 μm) was used to separate peptides at a flow rate of 0.200 mL/min. First, bovine serum albumin samples were analyzed with intra- and inter-day (11 days) experiments. In Escherichia coli experiments, 518 proteins were identified and subsequently investigated with PANTHER gene list and KEGG pathway. Results demonstrated that UPLC/MS provides detailed information regarding cellular process. Finally, we analyzed human plasma sample to observe if UPLC/MS system could be used to analyze body fluids. We identified 87 proteins in the plasma sample, and the identified proteins were investigated in terms of molecular biology. The results showed that UPLC/MS system could provide promising results for experimental and clinical proteomics. Keywords : Chromatography; maxquant; proteomics; E. coli; plasma