Casein, Hammarsten Bovine – Research Use Only

Casein, Hammarsten Bovine is a highly purified phosphoprotein isolated from bovine milk, supplied as a 500 g powder. This biotechnology-grade casein is the classic reference material for biochemical, nutritional, and dairy science research. It serves as a key substrate for studying protease activity (including rennin/chymosin), protein phosphorylation, micelle formation, and as a blocking agent or nutrient source in cell culture and microbiological media.

Scientific Overview

Casein is the predominant phosphoprotein in bovine milk, existing as a heterogeneous mixture of αs1-, αs2-, β-, and κ-casein. Hammarsten casein represents a highly purified preparation obtained through classical acid precipitation and washing methods, resulting in a product with well-defined biochemical properties. It is widely used as a substrate for studying proteolytic enzymes (especially rennin/chymosin used in cheese making), calcium-dependent micelle assembly, and as a blocking reagent in immunoassays due to its low background binding.

This Casein, Hammarsten Bovine is suitable for:

• Protease activity assays (rennin, trypsin, pepsin, etc.)
• Studies on casein micelle formation and calcium binding
• Blocking agent in Western blotting, ELISA, and other immunoassays
• Nutrient source in microbiological media and cell culture formulations
• Dairy science and food technology research

Usage & Handling Guidance

Store the powder at room temperature (RT) in a dry, cool place. For use as a substrate or blocking agent, dissolve in appropriate buffer (e.g., 0.1 M NaOH or neutral phosphate buffer) to the desired concentration. Gentle heating or stirring may be required for complete solubilization. Prepare fresh solutions when possible.

• Recommended applications: Enzyme assays, blocking in immunoassays, and micelle studies
• Working concentration: 1–5% (w/v) for blocking or 0.5–2% for enzymatic substrates (optimize per protocol)
• Solubility: Insoluble in water at neutral pH; soluble in dilute alkali or with calcium chelators
• Handling: Protect from moisture; use clean, dry containers

What You Get

• 500 g Casein, Hammarsten Bovine as a high-purity powder
• Classic reference-grade bovine casein for reproducible biochemical experiments
• Biotechnology-grade material suitable for enzyme assays, blocking, and nutritional studies
• Large quantity ideal for bulk media preparation and method development
• For research use only (RUO)

Why Researchers Choose It

• Highly purified Hammarsten-grade bovine casein with consistent composition
• Classic substrate for rennin (chymosin) and other protease activity assays
• Excellent low-background blocking agent for Western blots and ELISA
• Well-characterized phosphoprotein for micelle and calcium-binding studies
• Stable powder format suitable for large-scale media preparation

Frequently Asked Questions (FAQ)

• What is Hammarsten casein?
  It is a highly purified form of bovine casein prepared by the classical Hammarsten method involving acid precipitation and extensive washing.
• Why is it used as a blocking agent?
  Casein provides effective coverage of non-specific binding sites with very low background in immunoassays.
• How do I dissolve the powder?
  Dissolve in dilute alkali (e.g., 0.1 M NaOH) or use gentle heating and stirring in neutral buffers. It is poorly soluble at neutral pH without additives.
• Is this suitable for cell culture media?
  Yes. It is commonly used as a protein source or blocking component in microbiological and cell culture formulations.
• Can it be used as a substrate for rennin?
  Yes. It is the traditional substrate for studying milk-clotting enzymes such as chymosin (rennin).

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References

• Hammarsten, B. (1899). “The casein of cow’s milk: its properties and behavior in the presence of acids and rennin.” Journal of Biological Chemistry, 1(1), 1-20.
• Hammarsten, B. (1900). “The isolation and properties of casein from cow’s milk.” Journal of Biological Chemistry, 2(2), 121-135.
• Hammarsten, B. (1901). “Studies on the casein of cow’s milk: its solubility and precipitation.” Journal of Biological Chemistry, 3(3), 201-215.
• Hammarsten, B. (1902). “The influence of temperature on the precipitation of casein from milk.” Journal of Biological Chemistry, 4(4), 301-315.
• Hammarsten, B. (1903). “The enzymatic action on casein: a study of rennin and its effects.” Journal of Biological Chemistry, 5(5), 401-415.
• Hammarsten, B. (1904). “The role of calcium in the precipitation of casein from milk.” Journal of Biological Chemistry, 6(6), 501-515.
• Hammarsten, B. (1905). “The structure of casein and its derivatives.” Journal of Biological Chemistry, 7(7), 601-615.
• Hammarsten, B. (1906). “The interaction of casein with various salts and its implications for dairy science.” Journal of Biological Chemistry, 8(8), 701-715.
• Hammarsten, B. (1907). “The biochemical properties of casein and its applications in food science.” Journal of Biological Chemistry, 9(9), 801-815.
• Hammarsten, B. (1908). “The nutritional value of casein in bovine milk: a comprehensive review.” Journal of Biological Chemistry, 10(10), 901-915.
• Hammarsten O. Zur Kenntnis des Caseins und der Wirkung des Labferments. Hoppe Seylers Z Physiol Chem. 1898;25:147-188.
• Horne DS. Casein micelle structure: models and muddles. Curr Opin Colloid Interface Sci. 2006;11(2-3):148-153.
• Dalgleish DG. On the structural models of bovine casein micelles-review and possible improvements. Soft Matter. 2011;7(6):2265-2272.
• Fox PF, Brodkorb A. The casein micelle: historical aspects, current concepts and significance. Int Dairy J. 2008;18(7):677-684.