Category: Stock solution
Preparation of Stock Solution of Ampicillin (50 mg/ml)
Ampicillin is one of the most extensively used antibiotics as a selection marker in molecular biology and bacteriology. Ampicillin is available as Ampicillin anhydrous, Ampicillin trihydrate and Ampicillin sodium salt. Ampicillin sodium salt is often used to prepare stock solution as it has better solubility in water (>50 mg/ml in water). A 50 mg/ml stock solution of ampicillin can be prepared by dissolving 500 mg ampicillin sodium salt in water to a final volume of 10 ml.
Preparation of 2 X YT Medium
The 2 x YT medium, also known as a 2 x TY medium, is a rich medium. It is recommended for the growth and propagation of E. coli infected with the single strand filamentous bacteriophage M13. It can be prepared by dissolving 16 g tryptone, 10 g yeast extract, and 5 g Sodium chloride (NaCl) in water to a final volume of 1000 ml.
Preparation of 6X DNA Loading Dye (Bromophenol blue, Xylene Cyanol FF, Ficoll 400)
10 ml of 6x DNA loading dye containing Bromophenol blue, Xylene cyanol FF, and Ficoll 400 is prepared by dissolving 25 mg bromophenol blue, 25 mg xylene cyanol FF and 1.5 g Ficoll 400 in water to a final volume of 10 ml. The final solution (6x DNA loading dye) will contain 0.25% (w/v) bromophenol blue, 0.25% (w/v) xylene cyanol FF, and 15% (w/v) Ficoll 400.
Preparation of 0.5 M EDTA Solution from Disodium EthyleneDiamineTetraacetate Dihydrate (EDTA.Na2.2H2O)
EDTA’s ability to sequester divalent cations from solution without any precipitation makes it a suitable choice to stop an ongoing enzymatic reaction or protect DNA from degradation. Disodium salt of EDTA (EDTA.Na2.2H2O) is most commonly used to prepare 0.5 M EDTA stock solution. A 0.5 M EDTA solution can be prepared by dissolving 186.12 grams of EDTA.Na2.2H2O (Molecular Weight: 372.24) in water to a final volume of 1000 ml.