The proportional bias of four methods frequently used for determining low concentrations of protein was evaluated with human serum protein fractions (Cohn Fractions II, III, IV, and V).

Determining the protein concentration in your sample is an important step in any laboratory workflow that involves protein extraction and/or analysis. Knowing how much protein you have can help you compare results from one protein to another and from one experiment to the next.

In the Beer’s law equation (equation 1), the molar extinction coefficients are included (εmolar) and the molar concentrations are obtained. Therefore, the molar concentration should be multiplied by the molecular weight of the protein to express the final protein concentration in mg/mL.

BCA assay

Protein concentration can be estimated by measuring the UV absorbance at 280 nm; proteins show a strong peak here due to absorbance from Tryptophan and Tyrosine residues (commonly referred to as A 280). This can readily be converted into the protein concentration using the Beer-Lambert law (see equation below).

Mature human milk contains 3%–5% fat, 0.8%–0.9% protein, 6.9%–7.2% carbohydrate calculated as lactose, and 0.2% mineral constituents expressed as ash. Its energy content is 60–75 kcal/100 ml.

Concentration measures the amount of a substance dissolved in a volume of another substance. It can be measured in moles per liter, also called molarity.

Concentration Synonyms – WordHippo Thesaurus….What is another word for concentration?