Phosphate buffered saline tablets pbs ph 7

Azithromycin dihydrate (AZT) was supplied by Alfa Aesar. Phosphate buffered saline tablets (PBS) pH 7.4, ethanol, acetone, chloroform and methanol were purchased from Sigma–Aldrich (Burlington, MA, USA). Glycerol and Brij-35 were provided by Sharlau (Barcelona, Spain) and Fagron (Rotterdam, The Netherlands) respectively. Acetonitrile (ACN) was purchased from WVR (Avantor, Arnhem, The Netherlands). UPLC grade water was obtained from a Milli-Q Advantage A10 System with resistivity of 18.2 mΩ (Merk Millipore, Darmstadt, Germany).
Tryptone soy broth (TSB) and tryptone soy agar (TSA) were supplied by Conda-Pronadisa (Torrejón de Ardoz Madrid, Spain). Eagle’s Minimum Essential Medium (EMEM) was purchased from ATCC. Dulbecco’s modified Eagle’s medium (DMEM w/stable Glutamine), Dulbecco’s Phosphate Buffered Saline (DPBS), penicillin, streptomycin and amphotericin B were bought in Biowest. Fetal bovine serum (FBS) was supplied by Thermo Fisher Scientific (Waltham, MA, USA).
Bacteria strains, Staphylococcus aureus (ATCC 25923; Ielab, Las Atalayas, Alicante, Spain) and Pseudomonas aeruginosa (ATCC 10145; Ielab, Spain). Cell line A549 (ATCC–CCL–185) was a gift from P. Martin-Duque and used between passages 25–32 and Calu-3 (ATCC-HTB-55) was acquired in ATCC and used between passages 24–30.

Materials 4-nitrobenzenediazonium tetrafluoroborate 97% (4-NPD), tetrabutylammonium tetrafluoroborate 99% (BU₄NBF₄), 1-ethyl-3-(3-(dimethylamino)-propyl) carbodiimide hydrochloride (EDC), N-hydroxysuccinimide (NHS), ferrocene carboxylic acid (FCA), potassium chloride, acetonitrile (ACN) and phosphate-buffered saline tablets (PBS; pH 7.4) were all purchased from Sigma Aldrich (St. Louis, MO, USA) and used as received. All reagents were of analytical grade, and the deionised water was used for the cleaning of the glassy carbon electrodes. Highly ordered pyrolytic graphite (HOPG) was purchased from MikroMasc (Wetzlar, Germany) with the following specifications: grade ZYA, mosaic spread with the value of 0.4° ± 0.1°, double-sided and with thickness 1 mm and the size of 10 × 10 mm².
Biomarker amyloid-beta peptides Aβ ((1-42) (ab120301)) and anti-beta amyloid antibody (ab224275), specific to Aβ (1-42) peptide Aβ, were purchased from Abcam (Cambridge, UK).
Amyloid-beta (1-42) was supplied in the lyophilised form by Abcam (Cambridge, UK). It was then dissolved in 10 mM sodium hydroxide, followed by gentle Vortex for less than 1 min to make a homogeneous solution. The peptide stock solution was then aliquoted and stored at −20 °C. Under these highly alkaline conditions, the peptide is fully dissolved and exists only as monomers [43 (link)].

For all aqueous buffers and dilution steps, ultrapure water obtained from a Barnstead™ GenPure™ device from Thermo Fisher Scientific (Waltham, MA, USA) was used. Acetic acid, acetonitrile (ACN), formic acid, and phosphate-buffered saline tablets (PBS, pH 7.4) were obtained from Sigma-Aldrich (Schnelldorf, Germany). TCEP was purchased from Carl Roth GmbH (Karlsruhe, Germany). Dimethyl sulfoxide (DMSO) and human liver S9 fraction (total protein concentration of 20 mg/mL) were supplied by Thermo Fisher Scientific (Waltham, MA, USA). Human skin S9 fraction (total protein concentration of 5 mg/mL) was purchased from BioreclamationIVT (Westbury, NY, USA). The reference standards for hGH and U-¹⁵N-labelled IGF-I were obtained from Prospec (Rehovot, Israel), the respective standard for non-labelled IGF-I from Novozymes (Adelaide, Australia). U-¹⁵N-labelled 22 kDa hGH was provided by NovoNordisk (thanks to Christian Arsene, Braunschweig, Germany). Serum and urine samples were obtained from healthy human volunteers and stored frozen at −80 °C until usage. The sample collection was approved by the local ethics committee (#139/2021) and all participants provided written consent.