Metabolomics FAQ

• • What are the Analytical Methods for Polysaccharides?

  Polysaccharide analysis typically involves the processes of separation, identification, and quantification. Several analytical techniques are commonly employed, each with its own advantages depending on the application. These methods include:   High-Performance Liquid Chromatography (HPLC) HPLC is widely used for the separation and quantification of polysaccharides. Different types of chromatographic columns (e.g., reverse-phase, ion-exchange, or gel permeation) can be selected to separate polysacchar......

• • Are Five Biological Replicates Standard in Animal Metabolomics? Is Three Sufficient?

  In metabolomics research, biological replicates are essential for assessing experimental reproducibility and minimizing errors, thereby improving the reliability of the resulting data. To ensure accuracy and reproducibility, researchers typically perform multiple independent experiments.   In scientific research, three biological replicates are commonly used and widely accepted. However, if experimental conditions permit, increasing the number of replicates enhances statistical power and strengthens t......

• • How Can Metabolomics Results Be Further Validated?

  Following the acquisition of metabolomics data, a series of validation approaches are necessary to ensure result accuracy and reliability. The following methods are commonly employed:   1. Replication Experiments Experimental replication is fundamental for confirming metabolomics findings. Conducting multiple independent experiments allows assessment of result reproducibility and stability. At least three independent replicates are generally recommended for validation.   2. Standard Compound Validatio......

• • How Are Lipids Extracted in Lipid Metabolomics Research?

  Lipid metabolomics involves the comprehensive study of lipid molecules within cells and their dynamic changes. This field investigates lipid biosynthesis, metabolism, and their functions in physiological and pathological processes. Lipid extraction is a critical step in metabolomics research, and the following procedure outlines the standard method:   1. Sample Preparation Biological samples, such as blood, urine, cells, or tissues, are collected. To prevent degradation during collection and processin......

• • How to Collect and Process Blood Samples for Metabolomics Testing

  Blood Sample Collection 1. Collection Time It is best to collect blood samples at the same time point (e.g., in the morning on an empty stomach) to minimize the impact of biological rhythms. 2. Collection Method Venipuncture is typically used with sterile collection tubes, which may contain or lack anticoagulants depending on the subsequent processing and analysis requirements. 3. Sample Volume Usually, 1-2 mL of blood is required. Blood Sample Processing 1. Centrifugation Centrifuge the blood samples at...

• • What Is the Appropriate Range for R2 and Q2 Intercepts in PLS-DA

  In Partial Least Squares Discriminant Analysis (PLS-DA), R2 is used to measure how well the model fits the data, whereas Q2 assesses the model's predictive capability. Ideally, R2 should approach 1, and Q2 should also be a positive value, with values closer to 1 indicating better performance. During cross-validation, examining the intercepts of the regression lines for R2 and Q2 can provide insights into potential overfitting tendencies of the model.

• • Purification and Detection Methods of Polysaccharides

  Polysaccharides are macromolecules composed of multiple glycosyl units, which play significant roles in biological functions and have varied applications. Purification and detection of polysaccharides often require a combination of sophisticated techniques. Purification Techniques for Polysaccharides: 1. Gel Chromatography: This method includes Gel Permeation Chromatography (GPC) and Gel Affinity Chromatography (GAC), which separate polysaccharides based on size and affinity differences for effective.......

• • In Untargeted Metabolomics, What Is the Difference Between Performing PLS-DA Analysis and OPLS-DA Analysis

  PLS-DA (Partial Least Squares Discriminant Analysis) and OPLS-DA (Orthogonal Partial Least Squares Discriminant Analysis) are widely used multivariate statistical techniques in metabolomics for identifying metabolites that differ significantly between groups. While both methods are employed for classification and prediction tasks, they differ in their modeling approaches and interpretability.

• • How Can the OPLS-DA Permutation Test Plot Be Considered Not Overfitted

  When applying the OPLS-DA (Orthogonal Partial Least Squares Discriminant Analysis) model for permutation testing, it is crucial to evaluate the model's predictive accuracy, particularly the Q2 statistic, in relation to the distribution of Q2 values obtained from the permutations. Specifically: The Q2 statistic of the original model should exceed the distribution of Q2 values derived from the permuted datasets. This indicates that the model's performance with the original dataset is substantially better.....

• • How to Purify Polysaccharides Using a DEAE Column in Ion Exchange Chromatography?

  Polysaccharide purification methods vary based on the polysaccharide characteristics, desired purity, and experimental requirements. Common methods include gel filtration chromatography, ion exchange chromatography, affinity chromatography, thin-layer chromatography, and ultrafiltration. The DEAE (diethylaminoethyl) column, an anion exchange column, is commonly used in ion exchange chromatography to separate positively charged biological macromolecules from mixtures.   In ion exchange chromatography, ......