['Microbial biofilms form on central venous catheters and may be associated with systemic infections as well as decreased dialysis efficiency due to catheter thrombosis. The most widely used anticoagulant catheter lock solution in the US is sodium heparin. We have previously shown that sodium heparin in clinically relevant concentrations enhances Staphylococcus aureus biofilm formation. In the present study, we examine the effect of several alternative catheter lock solutions on in vitro biofilm formation by laboratory and clinical isolates of S. aureus and coagulase-negative staphylococci (CNS).', 'Lepirudin, low molecular weight heparin, tissue plasminogen activator, sodium citrate, sodium citrate with gentamicin and sodium ethylene diamine tetra-acetic acid (EDTA) were assessed for their effect on biofilm formation on polystyrene, polyurethane and silicon elastomer.', 'Sodium citrate at concentrations above 0.5% efficiently inhibits biofilm formation and cell growth of S. aureus and Staphylococcus epidermidis. Subinhibitory concentrations of sodium citrate significantly stimulate biofilm formation in most tested S. aureus strains, but not in CNS strains. Sodium EDTA was effective in prevention of biofilm formation as was a combination of sodium citrate and gentamicin. Low molecular weight heparin stimulated biofilm formation of S. aureus, while lepirudin and tissue plasminogen activator had little effect on S. aureus biofilm formation.'] Do catheter lock solutions influence staphylococcal biofilm formation on abiotic surfaces?