title: Fast determination of antibiotics in whole blood.
abstract: There is a need for analytical methods capable of monitoring blood antibiotic levels in real time. Here we present a method for quantifying antibiotic levels in whole blood that does not require any sample pretreatment. The tests employ the enzyme penicillinase to assay for penicillin G, penicillin V and ampicillin using a flow-injected biosensor, the Enzyme Thermistor. Optimal flow rates, sample volumes and pH were determined to be 0.5 mL/min, 100 μL and 7.0, respectively. Analysis of the antibiotics diluted in buffer gave a linear range of 0.17-5.0 mM. Calibration curves prepared using blood spiked with the antibiotics gave a linear range of 0.17-2.0 mM. Linear regression values for all of the calibration curves were 0.998 or higher. Assay cycle time was 5 min. The relative standard deviation value for 100 determinations of a mock blood sample spiked with penicillin G was 6.71%. Despite the elimination of sample pretreatment, no detectable clogging or signal drift was observed. The assay provides a fast, simple, reliable analytical method for determining antibiotic concentrations in blood without the need for any sample pretreatment. This is an important first step towards developing a device capable of real-time monitoring of antibiotic levels in whole blood. The technology has the potential to significantly improve the outcomes of patients undergoing critical care.
authors.affiliation: Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Medical School of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Andersson
authors.forename: M
authors.initials: M
authors.lastname: Mecklenburg
authors.forename: B
authors.initials: B
authors.lastname: Xie
mesh_terms: D000667:Ampicillin / Q000097:blood*; D000900:Anti-Bacterial Agents / Q000097:blood; D015374:Biosensing Techniques / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D010400:Penicillin G / Q000097:blood*; D010404:Penicillin V / Q000097:blood*; D010405:Penicillinase
chemical_list: D000900:Anti-Bacterial Agents; D000667:Ampicillin; D010405:Penicillinase; D010400:Penicillin G; D010404:Penicillin V