The Biuret test is a cornerstone in analytical chemistry and biochemistry, prized for its effectiveness in identifying and quantifying proteins. This method hinges on the detection of peptide bonds, the fundamental links that bind amino acids together to form protein molecules. At NINGBO INNO PHARMCHEM CO.,LTD., we supply high-grade Biuret Reagent, crucial for this indispensable assay.

The Scientific Principle of the Biuret Test

The magic of the Biuret test lies in its colorimetric nature. When Biuret reagent, containing copper(II) ions in an alkaline solution, interacts with a sample containing proteins, a distinct violet-purple color emerges. This color transformation is due to the chelation of Cu2+ ions with the nitrogen atoms present in the peptide bonds. The greater the number of peptide bonds, the more intense the color produced. This allows for a quantitative assessment of protein concentration, typically when measured using a spectrophotometer at approximately 540 nm.

Step-by-Step Procedure for Protein Detection

For any laboratory scientist or researcher aiming to buy Biuret Reagent, understanding the procedural steps is vital for accurate results:

  1. Sample Preparation: Ensure your sample is in an aqueous solution. For highly concentrated protein samples, dilution might be necessary to fall within the assay's detection range.
  2. Reagent Addition: Add the Biuret reagent to the sample. A common practice is to use an equal volume of Biuret reagent to the sample volume. It's crucial that the solution becomes alkaline, which is facilitated by the sodium hydroxide component of the reagent.
  3. Incubation and Observation: Gently mix the contents of the test tube or cuvette. Allow the reaction to proceed for about 5-10 minutes at room temperature. The appearance of a violet or purple color indicates a positive test for proteins. If the solution remains blue (the original color of the reagent), it suggests the absence of proteins or very low concentrations.

Key Applications of the Biuret Assay

The Biuret test finds broad utility across scientific and industrial fields:

  • Research and Development: Essential for quantitative protein analysis in molecular biology, biochemistry, and pharmaceutical research. Researchers often seek reliable suppliers in China for cost-effective, high-quality reagents.
  • Medical Diagnostics: Used in clinical pathology to measure total protein levels in serum, plasma, and cerebrospinal fluid, aiding in the diagnosis of conditions affecting protein metabolism.
  • Food Industry: Crucial for determining the protein content in various food products, ensuring nutritional accuracy and quality control.
  • Educational Settings: Provides students with hands-on experience in biochemical analysis and the principles of colorimetric assays.

The simplicity and affordability of the Biuret test make it a preferred method for many laboratories, despite its limitations in sensitivity compared to other assays. When you need to buy Biuret Reagent, choosing a reputable manufacturer like NINGBO INNO PHARMCHEM CO.,LTD. ensures you receive a product that guarantees the accuracy and reliability demanded by scientific research and diagnostic applications.