Iodine

Five µl of C. muridarum mutant isolates from the mutant library were used to infect fresh McCoy cell monolayers by centrifugation and rocking. At 28 hpi monolayers were fixed with 100% methanol for 10 min. Glycogen was assayed by staining with a 5% iodine solution (5% w/v iodine (Sigma), 5% w/v potassium iodide (Sigma), in a 50/50 solution of water and 100% ethanol) for 10 min, followed by staining with a 2.5% iodine solution (2.5% w/v iodine, 2.5% w/v potassium iodide, in a 50/50 solution of water and 100% ethanol) for 10 min. The iodine solution was removed and 100 µl PBS was added to each well. Plates were imaged using an EVOS® FL Auto cell imaging microscope. Glycogen deficient mutants were examined for mutations in known glycogen biosynthesis genes by Sanger sequencing or by whole genome sequencing as previously described (Rajaram et al., 2015 (link)). P2B10 carried a C393T mutation in glgA, and P3B4 carried a G1157A mutation in the same gene.

Chloro(triphenylphosphine)gold(I) (≥99.9% trace metals basis, Aldrich), 1-Octanethiol (≥98.5%, Aldrich), 3-Mercaptopropionic acid (HPLC, ≥99.0%, Aldrich), 3-Mercaptopropionic-2,2,3,3-d4 Acid (98 atom % D, C/D/N Isotopes Inc.), borane t-butylamine complex (97%, Aldrich), Acetone(HPLC, ≥99.8%, Aldrich), MEthanol (HPLC, ≥99.9%, Aldrich), Ethanol (HPLC, ≥99.8%, Aldrich), Chloroform (HPLC, ≥99.9%, Aldrich), Toluene (HPLC, 99.8%, Aldrich), Sulfuric acid (98.0%, Aldrich), (3-Mercaptopropyl)trimethoxysilane (95%, Aldrich), Hexane (99%, Aldrich), Iodine (≥99.99% trace metals basis, Aldrich), Tetrahydrofuran-d8 (≥99.5 atom % D, Aldrich), Chloroform-d (99.8 atom % D, Aldrich), MEthanol-d4 (99.96 atom % D, Aldrich). All chemicals were used as received.

Poly(ethylene glycol) methyl ether methacrylate M_n = 300 g mol⁻¹ (OEGMA, Aldrich Chemical Co. Toluca, Edo. México, México) and di(ethylene glycol) methyl ether methacrylate (DEGMA, Aldrich Chemical Co.), were purified by passing through a column packed with inhibitor remover for hydroquinone and monomethyl ether hydroquinone (Aldrich Chemical Co.) and neutral alumina (Productos Químicos Monterrey, Monterrey, N.L. México) before use. Propane-1-thiol (Aldrich Chemical Co., ≥99%), carbon disulfide (Aldrich Chemical Co., ≥99.9%), sodium hydroxide pellets (Productos Químicos Monterrey 97.8%), acetone (J.T. Baker, Xalostoc, Edo. México, México 99.6%), ethyl acetate (Fermont, Monterrey, N.L. México 99.9%), methylene dichloride (Fermont ≥ 99.9%), diethyl ether (Fermont, ≥99.9), tetrahydrofuran (Aldrich Chemical Co. ≥99.9), potassium iodide (Fermont 99.8%), iodine (Aldrich Chemical Co. ≥ 99.8%), 4,4-azobis(4-cyanovaleric acid) (ACVA) (Aldrich Chemical Co., ≥98%), and anhydrous magnesium sulfate (Fermont, 99.8%) were used as received.

The substrate that consists of a scattering layer and Au NP-loaded f-TNTAs was soaked in a ruthenium dye (Bu₄N)₂Ru(dcbpyH)₂(NCS)₂ (N719, Solaronix, Aubonne, Switzerland) solution at 50 °C for 8 h. Eventually, the substrate was fully coated with N719 and was used as the working electrodes of DSSCs. The platinum (Pt) layer was prepared by dropping 0.5 mM of a H₂PtCl₆·6H₂O (Aldrich, St. Louis, MI, USA) solution on the FTO glass, followed by heating at 300 °C for 30 min as a counter electrode. Each of the counter and working electrode were assembled into a sandwich-type cell and were sealed using a hot-melt film (Surlyn-1702, Dupont, Mississauga, ON, Canada) on a hotplate. The space between the two electrodes was filled with an electrolyte containing 0.7 M 1-butyl-3-methyl-imidazolium iodide (BMII, 99%, Aldrich, St. Louis, MI, USA), 0.03 M iodine (99%, Aldrich, St. Louis, MI, USA), 0.1 M guanidium thiocyanate (GSCN, 99%, Aldrich, St. Louis, MI, USA), and 0.5 M 4-tertbutylpyridine (TBP, 96%, Aldrich, St. Louis, MI, USA) in an 85/15 (v/v) solution of acetonitrile and valeronitrile.

To prepare photoanodes titania electrodes were immersed in a 1 × 10⁻⁴ M solution of N719 (Solaronix) or B1 (synthesized by us31 ) dye in absolute ethanol or in a mixture of 1 × 10⁻³ M chenodeoxycholic acid (Solaronix) and 1 × 10⁻⁴ M SQ2 (Solaronix) dye in absolute ethanol at room temperature overnight. A platinum coated FTO was used as a counter electrode and a mixture of 0.6 M 1-butyl-3-methyl imidazolium iodide (Aldrich), 0.06 M lithium iodide (Aldrich), 0.03 M iodine (Poch), 0.1 M guanidinium isothiocyanate (Aldrich), 0.5 M 4-tert-butylpyridine (Aldrich) in acetonitrile was used as an electrolyte. The cell was assembled according to the procedure described in our previous work31 . UV-VIS absorbance spectra of 2 × 10⁻⁵ M dye solutions (N719, B1, SQ2) in dry ethanol were measured by a UV-VIS spectrophotometer (Lambda 35, Perkin Elmer). The morphology of the titania electrodes was characterized by Schottky field emission scanning electron microscopy (FEI Quanta FEG 250).

Tellurium (200 mesh, 99.85%), selenium, sulfur, sodium borohydride (powder, 98%), bromine, iodine, n-butyl lithium solution, and 1-bromobutane (BuBr, 99%) were purchased from Aldrich. Sodium sulfite was purchased from EMScience. Tetrabutylammonium bromide (TBAB, 98%) was obtained from Alfa Aesar, and hydrogen tetrachloroaurate hydrate (49 wt% Au) was obtained from Strem Chemicals. The organic solvents dimethyl formamide, hexane, toluene, methanol, dichloromethane, ethanol, and tetrahydrofuran were of analytical grade. They were all used as received. Milli-Q water (18.2 MΩ) was used. All glassware was cleaned in sulfuric acid with Nochromix and rinsed with a large amount of water before use.
Di-butyl disulfide was prepared by addition of n-butyl lithium (1 eq.) to a THF suspension of elemental sulfur followed by water and iodine. A similar procedure was adopted to prepare dibutyl ditelluride, omitting the treatment of the reaction media with iodine and exposing the intermediate tellurol to an oxygen atmosphere for the oxidation step. Di-butyl diselenide was prepared by reacting elemental selenium in aqueous basic media with hydrazine hydrate followed by addition of butyl bromide and Tetrabutylammonium bromide. The synthetic reaction is summarized in Fig. 6. A detailed experimental procedure is presented in the ESI.†