Understanding Nycodenz: A Technical Overview

Nycodenz is a non-ionic, low-osmolar, iodinated gradient medium widely utilized in biological and biochemical research for the separation, purification, and characterization of various biological materials. This article provides a technical overview of Nycodenz, outlining its composition, properties, applications, and principles of operation.

Schematic outline of Nycodenz density gradient fractionation

Composition and Properties of Nycodenz

Nycodenz, also known by its chemical name iohexol, is a water-soluble, iodinated contrast agent originally developed for medical imaging applications. However, its unique properties, including its low osmolarity and non-ionic nature, make it well-suited for use as a gradient medium in density gradient centrifugation techniques.

Nycodenz typically exists in the form of a white, crystalline powder, which is easily soluble in water to produce a clear, colorless solution. Its density ranges from approximately 1.32 to 1.41 g/ml, depending on the concentration and temperature, allowing for precise adjustments to match the density of the biological material being separated.

Applications of Nycodenz

  1. Cell Separation: Nycodenz is commonly employed in the isolation and purification of various cell types from complex mixtures, such as blood or tissue samples. By layering the sample onto a gradient of Nycodenz and subjecting it to centrifugation, different cell populations can be separated based on their buoyant densities.
  2. Viral Purification: Nycodenz is utilized in the purification of viruses from biological samples, facilitating the concentration and isolation of viral particles for further analysis or vaccine production. The density gradient centrifugation technique employing Nycodenz allows for the separation of viruses from cellular debris and other contaminants.
  3. Organelle Isolation: Nycodenz is also employed in the isolation and purification of subcellular organelles, such as mitochondria, lysosomes, and nuclei, from cellular lysates. By exploiting the density differences between organelles and other cellular components, Nycodenz gradient centrifugation enables the enrichment of specific organelle fractions.

Principles of Nycodenz Gradient Centrifugation

The principle behind Nycodenz gradient centrifugation is based on the differential sedimentation of particles in a density gradient. When a sample containing heterogeneous components is layered onto a gradient of Nycodenz and subjected to centrifugation, the particles migrate through the gradient until they reach a position where their density matches that of the surrounding medium. This results in the formation of distinct bands or layers containing particles of similar buoyant densities.

 Evaluation of quantitative recovery of bacterial cells and DNA from different lake sediments by Nycodenz density gradient centrifugation


Nycodenz plays a critical role in various aspects of biological and biochemical research, offering researchers a versatile tool for the separation, purification, and characterization of biological materials. Its unique properties, including its low osmolarity, non-ionic nature, and adjustable density, make it well-suited for applications ranging from cell separation to organelle isolation. As researchers continue to explore novel applications and refine techniques utilizing Nycodenz, its importance in biomedical research is expected to persist, contributing to advancements in our understanding of cellular and molecular biology.

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