Chloramphenicol is an antibiotic, isolated from strains of Streptomyces venezuelae. It blocks bacterial protein synthesis by inhibiting the peptidyl transferase activity of the 50S ribosomal subunit. The antibiotic has a broad application range against gram positive and gram negative bacteria.Chloramphenicol is used for bacterial selection and plasmid amplification in molecular biology applications and as a selection agent for transformed cells containing chloramphenicol reistance genes.A stock solution opf 50 mg/ml in ethanol yield a clear, very faint yellow solution. For selection of chloramphenicol-resistant Escherichia coli a concentration of 30 - 50 µg/ml are typically used. Chloramphenicol is an antibiotic, isolated from strains of Streptomyces venezuelae. It blocks bacterial protein synthesis by inhibiting the peptidyl transferase activity of the 50S ribosomal subunit. The antibiotic has a broad application range against gram positive and gram negative bacteria.Chloramphenicol is used for bacterial selection and plasmid amplification in molecular biology applications and as a selection agent for transformed cells containing chloramphenicol reistance genes.A stock solution opf 50 mg/ml in ethanol yield a clear, very faint yellow solution. For selection of chloramphenicol-resistant Escherichia coli a concentration of 30 - 50 µg/ml are typically used.