Related Experiment Video
Updated: Aug 17, 2026

A Protocol to Set Up Needle-Free Connector with Positive Displacement on Central Venous Catheter in Intensive Care Unit
Published on: July 13, 2019
Tetrasodium EDTA as a novel central venous catheter lock solution against biofilm
Steven L Percival1, Peter Kite, Kerrie Eastwood
1Department of Microbiology, Leeds Teaching Hospitals, Leeds, United Kingdom.
Background:
Central venous catheter (CVC)-related bloodstream infections (BSIs) are known to increase rates of morbidity and mortality in both inpatients and outpatients, including hematology-oncology patients and those undergoing hemodialysis or home infusion therapy. Biofilm-associated organisms on the lumens of these catheters have reduced susceptibility to antimicrobial chemotherapy. This study tested the efficacy of tetrasodium EDTA as a catheter lock solution on biofilms of several clinically relevant microorganisms.
Methods:
Biofilms of Staphylococcus epidermidis, methicillin-resistant S. aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Candida albicans were grown to levels of approximately 1 x 10(5) colony-forming units (CFU)/cm(-1) on CVC segments in a model system, then subjected to the tetrasodium EDTA lock treatment.
Results:
Comparisons of biofilms before and after exposure to the 40-mg/mL(-1) tetrasodium EDTA lock for 21 hours showed that the biofilm viable cell counts of all organisms tested were significantly reduced (P < .05) after exposure to the treatment.
Conclusion:
Antimicrobial lock treatment using 40 mg/mL(-1) of tetrasodium EDTA for at least 21 hours could significantly reduce or potentially eradicate CVC-associated biofilms of clinically relevant microorganisms.
Related Concept Videos
Effects of EDTA on End-Point Detection Methods
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
EDTA: Chemistry and Properties
EDTA: Auxiliary Complexing Reagents
Masking and Demasking Agents
There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on the metal...
EDTA: Indirect and Alkalimetric Titration
EDTA: Direct, Back-, and Displacement Titration
Direct titration involves buffering the metal ion solution to the desired pH and directly titrating with standard EDTA until the endpoint. The optimum pH ensures a large conditional formation constant of metal−EDTA and visibility of the free indicator color in the solution. In addition, auxiliary complexing reagents are used to prevent the precipitation of metal hydroxides and...

