Mg2+ is a cofactor of the enzyme peroxidase. In order to keep the enzyme active, this cofactor must be supplied. Magnesium chloride dissociates in solution into magnesium and chloride ions. The cofactor requirement is thus met
It solubalize lipids and protiens to remove them from DNA
In the laboratory, it may be used as a milddrying agent where other drying agents, such as calcium chloride and magnesium sulfate, may be incompatible. It is not suitable for acidic compounds, but can be useful for drying an organic phase if one has a small amount of acidic impurity.
Phenol and chloroform are very hydrophobic and are used to remove non-polar bio- molecules (proteins, fragments of membranes, lipids etc) in the extraction.
it helps keep the ph stable
This is a loose question. Since the most well known use for salt is in human diet, we could start an answer in this context. To replace dietary sodium chloride salt completely with potassium could well have fatal effects. Sodium chloride is essential for the function of the nervous system. However a high sodium (ion) intake can also be fatal. In the last few years, low sodium (ion) salts have been marketed. These might have as little 35% of the sodium of typical sodium chloride table salt, the substitute for the missing sodium is sometimes purely potassium chloride and sometimes potassium with some magnesium.
Yes. Potassium, along with sodium, chloride, calcium, and magnesium, is an important electrolyte necessary for proper cellular function.
use for extraction the caffeine
In lysis buffer, the function of ammonium chloride is to determine the red blood cells in samples. These samples also contain white blood cells.
chelating Mg2+
Sodium chloride function as electolytes.
removal of polyphenols
To achieve precipitation DNA.
potassium magnesium doesn't exist. They are two separate "metals".
DTT is the reducing agent for thiolated DNA
salt binds to molecules to keep it from clumping
It solubalize lipids and protiens to remove them from DNA
from Wikipedia on "Salt" "Sodium is one of the primary electrolytes in the body. All four cationic electrolytes (sodium, potassium, magnesium, and calcium) are available in unrefined salt, as are other vital minerals needed for optimal bodily function."