Label-free quantitative proteomic analysis of Brucella abortus and Brucella melitensis

Brucella type strains (B. abortus 544 and B. melitensis 16 M), field-isolates (B. abortus T and B. melitensis C) were independently cultivated six times on Tryptic Soy Broth at 37 °C in the presence of 5% CO2 until mid-logarithmic phase. The cells were harvested by brief centrifugation and the bacteria was inactivated using recommended ethanol precipitation procedure. Following which the cells were lysed, proteins quantified and the differentially expressed proteins among B. abortus and B. melitensis were identified using liquid chromatography-mass spectrometry (LC/MS) based label free quantitative proteomics analysis.