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Stability Constants for Metal Ion–EDTA Complexes
Metal Ion-EDTA complex Stability constant (log kf) Al3+–EDTA complex 16.4 Ca2+–EDTA complex 10.65 Cd2+–EDTA complex 16.5 Co2+–EDTA complex 16.45 Co3+–EDTA…
Preparation of Stock Solution of Ethidium Bromide (10 mg/ml)
Overview: Ethidium bromide (EtBr) is a commonly used fluorescent stain to visualize nucleic acid especially DNA in agarose gels. Ethidium…
Molarity of Commercially Supplied Concentrated Acids and Bases
Acids / bases Molecular formula Molecular weight Strength of Concentrated reagent as supplied commercially Specific gravity (g/ml) at 25 °C…
Preparation of Stock Solution of Chloramphenicol (34 mg/ml)
Overview Chloramphenicol is a broad-spectrum antibiotic that is effective against both gram-positive and gram-negative bacteria. It is a bacteriostatic agent….
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.
Tracking Dye
Tracking dyes are colored dyes, which are added to the loading dye/buffer. Loading dye/buffers are used to prepare samples for…
Preparation of 20% (w/v) Sodium Dodecyl Sulfate (SDS) Solution
Overview Sodium dodecyl sulfate (SDS, CH3(CH2)11OSO3Na, molecular weight 288.38 g/mole, CAS Number 151-21-3) is an anionic surfactant (detergent) and is…
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 1 M Dithiothreitol (DTT) Solution
Overview DTT (DTT, C4H10O2S2, molecular weight 154.25 g/mole) is also known as Cleland’s reagent. DTT is commonly used for the…
Suppliers – Ammonia /Ammonium hydroxide solution in water
Note: We have listed some suppliers. You must visit the supplier’s homepage to order and to get more details about…
Plasmid Isolation
To isolate plasmid from the host bacteria, cells are first lysed that lead to the release of plasmid and in subsequent steps, the plasmid is purified from the lysate. Purification of plasmid from the lysed cells are mostly dependent on the type of lysis method used to release plasmid in solution. For example, alkaline lysis which completely disrupts the bacterial cells leading to the release of cell components including both plasmid DNA and genomic DNA in denatured state relies on selective renaturation of only plasmid DNA in a perfect manner at the purification step. On the other hand, boiling lysis selectively releases only plasmid DNA from the bacterial cells. The purified plasmid can be further purified by a number of methods to obtain high quality plasmids. These methods are centrifugation in gradients of CsCl – ethidium bromide (EtBr), selective precipitation in high salt SDS, extraction with Phenol-chloroform, and hydroxylapatite and ion-exchange chromatography.
Ethylenediaminetetraacetic Acid (EDTA)
EDTA is a polyaminocarboxylic acid. Its conjugate base is ethylenediaminetetraacetate. It is a colorless compound that was first synthesized by…
Phenol-Chloroform Extraction of Nucleic Acid
Phenol-chloroform extraction can be used to isolate and purify nucleic acid (DNA and RNA). It is a very reliable method…
Growing Escherichia coli for Plasmid Isolation
Amplification of plasmid is desirable for many applications including gene cloning, DNA sequencing, transfection, and probe preparation. The fastest and routinely used method to amplify plasmid is to introduce plasmid in an appropriate strain of E. coli e.g., DH5α (the process is called transformation), grow them to a suitable culture volume, and finally, extract plasmid from them (the process called plasmid isolation).
Comparison of TAE and TBE Electrophoresis Buffers
Both TAE (Tris-Acetate EDTA) and TBE (Tris-Borate EDTA) are common electrophoresis buffers for DNA agarose gel electrophoresis. However, they are quite different in nature, have some useful features and also some disadvantages. You can maximize your results by choosing an electrophoresis buffer depending on your application. The following table lists their properties, and advantages and disadvantages, and also provides explanation for their peculiar behaviour.