Hi

Kinga Graniczkowska

Looking to the Hammarsten grade casein is giving better results because it is homogeneous protein. However, bovine casein is not homogeneous

shenana

Dear Shenana, 

Thank you very much for your kindly answer.

Kinga  

Hi,

I did a quick research for references to help me understand what this Hammarsten casein is, and what I found sais it is actually acid precipitated casein, resuspended with High pH and washed again 5 times. But basically it is sodium caseinate, much like the one you're using.

If there is a relevant difference, it might rather be in the drying process and in the solubilisation. As caseins are quite hydrophobic proteins, it may sometimes be difficult to resuspend them.

In my experience, however, BSA is a very good blocking agent, and we commonly use powdered instant skim milk, too, why are you using precisely sodium caseinate?

Casein, Hammarsten is different from the "regular" acid caseins by an additional alcohol washing step tp remove carbohydrates and fat content. Therefore, other than the high purity Hammarsten Casein can be considered carbohydrate and fatty acid free.

"casein, as practised by Hammarsten, consists in treating milk with acetic acid, and dissolving the precipitate in dilute ammonia or sodium carbonate, an alkaline reaction being guarded against. This operation is repeated, and the casein is treated with alcohol and ether to completely eliminate the contained fat, a second treatment with acetic acid and soda being afterwards given. Provided a strongly alkaline reac-

tion is avoided, the casein is not decomposed."

Hope this helps..

Mr. Orbulescu, 

Thank you for for your kindly answer.

Kinga