- Tetracyclines are a group of broad-spectrum antibiotics. They are active against wide range of microorganisms including bacteria (both gram positive and gram negative), chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites.
- Tetracyclines function by inhibiting the protein synthesis.
- Binding of tetracyclines to 30S ribosomal subunit prevent access of aminoacyl tRNA to the acceptor site on the mRNA – ribosome complex, leading to inhibition of protein synthesis.
- Tetracycline hydrochloride can be used for biological research.
- Tetracycline hydrochloride is soluble in water (50 mg/ml) with heating.
- It forms a clear, yellow to yellow-orange solution in water.
- It also forms a clear, yellow-green solution in 95% ethanol.
- Tetracycline is rapidly destroyed by alkali hydroxide solutions and solutions in water become turbid on standing due to hydrolysis and precipitation of tetracycline.
- The potency of tetracycline is reduced in solutions with pH below 2.
- A 5 – 12 mg/ml stock solution of tetracycline is generally prepared in 70% ethanol. Stock solution is diluted to final concentration, depending on the need.
- Magnesium ions are antagonistic to tetracycline, therefore, don’t use magnesium salt in bacterial culture medium if tetracycline is going to be used for selection. This may lead to false positives.
- Tetracycline hydrochloride (C2H24N2O8.HCl) (Molecular weight: 480.9)
- 70% ethanol
- Equipment and disposables
- Measuring cylinder
- Conical flask / Beaker / 15 ml screw-capped tube
- Magnetic stirrer
- 12 mg/ml tetracycline
- 70% ethanol
- Preparation of 10 ml of tetracycline stock solution (12 mg/ml) in 70% ethanol
Step 1: To prepare 10 ml of 12 mg/ml tetracycline stock solution, weigh out 120 mg of tetracycline. Transfer it to 15 ml screw-capped tube. Add 9 ml of 70% ethanol. Mix until all tetracycline dissolves completely.
- We recommend to use 15 ml screw-capped tube with millilitre marks. Transfer all the contents in it. Add 9 ml 70% ethanol and mix the content by rotating the tube. Once the content is mixed, make up the volume 10 ml.
- Do not dissolve in 10 ml of deionized / Milli-Q water. In most cases, solution volume increases when the large amount of solute dissolves in solvent.
Step 2: Adjust the volume to 10 ml with 70% ethanol. Mix it again.
Store the solution in small aliquots (1 ml) at -20°C for long time.
- Protect the solution from light.
- A selection marker for bacterial culture during gene cloning experiments.
- Often used for inducible expression system (tet-on tet-off) in mammalian cells.
|Follow the table to prepare tetracycline stock solution of various volume (5 ml, 10 ml, 25 ml, 100) and concentration.|
|Conc. / Volume||5 ml||10 ml||25 ml||100 ml|
|5 mg/ml||25 mg||50 mg||125 mg||500 mg|
|10 mg/ml||50 mg||100 mg||250 mg||1000 mg|
|12 mg/ml||60 mg||120 mg||300 mg||