M7506

2.9 g NaCl (Sigma-Aldrich M7506), 0.49 g CaCl₂ (Sigma-Aldrich P5405), 0.13 g KCl (Sigma-Aldrich P5405), 0.81 g MgSO₄ (Sigma-Aldrich M7506).

The effect of ITD-13 on biofilm formation was examined for the Mtb H37Rv strain by performing biofilm assays in the absence and presence of the compound (MIC₅₀ and MIC₉₀). Growth of Mtb biofilms was determined in Sauton’s medium [0.5 g of KH₂PO₄, 0.5 g of MgSO₄ (M7506, Sigma), 4 g of L-asparagine (A4159, Sigma), 2 g of citric acid (C2404, Sigma), 0.05 g of ferric ammonium citrate (F5879, Sigma), 60 mL of glycerol (G2025, Sigma), and 900 mL of deionized water, pH 7.0 in 24-well plates, as previously described with some modifications [19 (link)]. Immediately before the experiment, sterile ZnSO₄ (Z0251, Sigma) was added to a final concentration of 0.1% w/v. Briefly, H37Rv was cultured to OD₆₀₀ = 1 in 7H9 medium supplemented with 10% OADC and 0.05% Tween 80. Next, the inoculum was added at a ratio of 1:100 v/v to Sauton’s medium, and then the obtained mixture was dispensed into each well of a 24-well plate (2.5 mL/well). The plate was covered with a lid, carefully wrapped with parafilm, and further incubated undisturbed in a humidified microbiological incubator at 37 °C for 5 weeks.

116 mM NaCl (Sigma-Aldrich M7506), 2.9 mM KCl (Sigma-Aldrich P5405), 1.8 mM CaCl₂ (Sigma-Aldrich P5405), 5 mM HEPES (Sigma-Aldrich H3375), adjusted to pH 7.2 using NaOH (1 M) (Sigma-Aldrich S5881) or HCl (1 M) (Applichem A0659).