Category: Stock solution

Preparation of 1M MOPS (Free Acid) Solution

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

Preparation of 6X DNA Loading Buffer (Orange G, Xylene Cyanol FF and Ficoll 400)

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.

Preparation of SOB (Super Optimal Broth) Medium

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.

Preparation of Alkaline Phosphatase Buffer

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

Preparation of 1M IPTG Solution

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

Preparation of Tris-saturated Phenol

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

Preparation of 4% Paraformaldehyde Solution in PBS

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

Preparation of 10 M Sodium Hydroxide (NaOH) Solution

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.

Preparation of 1 M Tris.Cl Buffer

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

Preparation of DNase-free Bovine Pancreatic RNase A

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

Preparation of 50X TAE Electrophoresis Buffer

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. 

Preparation of 5X TBE Electrophoresis Buffer

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.

Preparation of Stock Solution of Tetracycline (12 mg/ml)

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

Preparation of Stock Solution of Streptomycin (50 mg/ml)

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

Preparation of Stock Solution of Kanamycin (50 mg/ml)

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