Doxycycline (Hyclate), 1 g

From STEMCELL Technologies, this tetracycline-like antibiotic is supplied as the hyclate salt and is intended for laboratory and research use. In genetic engineering, it is used as the regulator for inducible gene expression systems, where expression depends on either the presence (Tet-On) or absence (Tet-Off) of the compound. The product also inhibits certain matrix metalloproteinases, including MMP-8 (Ki = 36 µM), while only poorly inhibiting MMP-1 and MMP-13 (Ki > 100 µM).

Provided as a crystalline solid with a stated purity of ≥ 98% and a molecular weight of 1025.9 g/mol, the compound carries OSHA hazard classifications for acute oral toxicity, skin and eye irritation, and respiratory irritation, and is harmful if swallowed. Recommended handling includes wearing protective gloves and eye protection, avoiding contact with skin, eyes and clothing, and not eating, drinking or smoking when using the product. It should be kept in tightly closed containers in a dry, cool, well-ventilated place, stored at -20 °C as supplied and protected from prolonged exposure to light, where it remains stable for 12 months from the date of receipt.

Solubility values given by the manufacturer are ~3 mg/mL in PBS (pH 7.2) and ~1 mg/mL in DMSO and DMF. When used as a cell culture supplement, the stock solution should be diluted into culture medium immediately before use, avoiding a final DMSO concentration above 0.1% due to potential cell toxicity. The product also carries a California Proposition 65 warning regarding birth defects or other reproductive harm.