Category: Stock solution

Overview MOPS (Free acid, C7H15NO4S, Molecular weight: 209.26) is a zwitterionic buffer, useful for several cell and molecular biology applications…

A 10 ml of 6X DNA loading dye can be prepared by dissolving and mixing 40 mg orange G, 25 mg xylene cyanol FF, 1.5 g Ficoll 400 and 0.1 ml of 1M Tris.Cl, pH 7.6 in sterile deionized or distilled water to a final volume of 10 ml.

SOB (Super Optimal Broth) medium is a nutrient-rich microbial growth medium, designed by Douglas Hanahan in 1983. SOB or its glucose-supplemented version SOC is often used during transformation of E. coli competent cells with plasmids (added in transformed cells after heat shock). It results in better survival and higher transformation efficiency as compared to regular LB medium. It contains 2% Bacto-tryptone, 0.5% Bacto-yeast extract, 0.05% Sodium chloride, 2.5 mM KCl, and 10 mM MgCl2. A 1000 ml SOB medium is prepared by dissolving 20 g bacto-tryptone, 5 g bacto-yeast extract, 0.5 g sodium chloride and 2.5 ml of 1M KCl in water to a final volume of 1000 ml. Medium is sterilized by autoclaving. MgCl2 (5 ml of 2M MgCl2) is added just before use.

Overview: An alkaline phosphatase buffer is required for the detection of alkaline phosphatase activity.  It contains 5 – 50 mM…

Overview: In molecular biology laboratories, IPTG is commonly used to induce the expression of recombinant proteins in E. coli and…

Overview: Phenol is a colorless crystalline solid. Phenol gradually turns pink to brownish color due to oxidation upon exposure to…

OVERVIEW A 4% paraformaldehyde in PBS is frequently used to fix biological samples. Paraformaldehyde is a white crystalline solid powder,…

Here we have described a procedure to prepare 10 M (or 10 N) sodium hydroxide (NaOH) solution. A 10 M NaOH solution can be prepared by dissolving 40 g of NaOH (Molecular Weight: 40.00) in water to a final volume of 100 ml. Since dissolution of NaOH in water is a highly exothermic reaction, extreme care must be taken while preparing the solution.

Overview Tris is also known as THAM, Tris base, Trizma, Tris(hydroxymethyl)aminomethane. Tris is one of the most frequently used buffers…

Overview Bovine pancreatic RNase (RNase A) is an endoribonuclease. It specifically degrades single-stranded RNA at C and U residues at…

A 50x TAE buffer can be prepared by mixing and dissolving 242 g Tris base, 100 ml of 0.5 M EDTA and 57.1 ml glacial acetic acid in a deionized water to a final volume of 1000 ml. The pH of the final solution should be between 8.2 – 8.4. 

TBE is a very common electrophoresis buffer for DNA agarose gel electrophoresis. It is prepared as a 5X stock solution that can be diluted to 1x or 0.5x working solution for DNA agarose gel electrophoresis. The 5X concentrated solution contains 0.445 M Tris borate and 0.01 M EDTA (pH 8.2 – 8.4).

A 5X stock solution is prepared by dissolving 54 g Tris base, 27.5 g Boric acid, and 20 ml of 0.5 M EDTA in water to a final volume of 1000 ml. The solution is sterilized by autoclaving and is stored at room temperature.

Overview Tetracyclines are a group of broad-spectrum antibiotics. They are active against a wide range of microorganisms including bacteria (both…

Overview Streptomycin function by inhibiting protein synthesis in bacteria. Binding of streptomycin to the small 16S rRNA of the 30S…

Overview Kanamycin is a water-soluble, aminoglycoside bactericidal antibiotic. It was originally purified from the bacterium Streptomyces kanamyceticus. It inhibits protein…