Metabolomics analysis I. Selection of biological samples and practical aspects preceding sample preparation

Metabolomics is one of the most recently emerged “-omics” sciences. Its significance in systems biology is gaining interest to levels similar to proteomics, transcriptomics and genomics. One of the main limitations in metabolomics analysis is the lack of totally comprehensive approaches and in-depth studies, as individuals or laboratories with different skill sets usually develop these. This variability particularly affects sample preparation due to the extensive heterogeneity of biological samples.This two-part review aims to offer a practical guide to preparing biological samples in metabolomics in order to reach the current level in genomics and proteomics. The first part focuses on analytical criteria for sample selection and operations that precede sample preparation.