Sample preservation is crucial for maintaining the integrity of specimens for accurate analysis. Various methods are used, depending on the sample type and intended analysis.
Preservation Techniques: A Broad Overview
A preservation technique aims to minimize degradation of sample components. This involves applying specific measures to maintain the chemical state of the sample. Common methods include:
- Refrigeration: A practical and reliable field method for many samples, readily available and minimally invasive. (Source: Missouri Extension publication)
- Adding Acids or Bases: Used to stabilize pH and prevent chemical changes. This requires careful handling due to safety hazards. (Source: EPA's Quick Guide To Drinking Water Sample Collection)
- Specialized Containers: Containers designed to protect against contamination and degradation, such as those used for preserving microbiota profiles at ambient temperature. (Source: Norgen Biotek Stool Collection and Preservation Devices)
- Chemical Additives: Specific chemicals can be added to inhibit microbial growth or prevent chemical reactions that alter the sample's composition. (Source: ScienceDirect Topics on Preservation Techniques). Examples include the BD® OMICS-Guard Sample Preservation Buffer for preserving biological samples over extended periods. (Source: BD Biosciences OMICS-Guard)
- Proprietary Preservation Techniques: Some companies offer specialized kits containing proprietary solutions for optimal sample preservation, ensuring consistent results, like LuminUltra's GeneCount® qKit Preserve. (Source: LuminUltra GeneCount® qKit Preserve)
Factors Affecting Sample Quality
The quality of environmental data relies on four fundamental aspects: sample collection, preservation, analysis, and data recording. Neglecting any step compromises data integrity. (Source: EPA Handbook for Sampling and Sample Preservation)
Examples of Sample Preservation Across Different Fields
- Breast tissue samples: Preserved tissue is stored at the hospital for potential future use. (Source: Komen Preserving Breast Tissue Samples)
- Wastewater samples: Refrigeration is often the preferred method for field preservation. (Source: Missouri Extension publication)
- Microbial samples: Methods prioritize preventing degradation and contamination. (Source: National Academies of Sciences, Engineering, and Medicine report)
- Urine and stool samples: Specialized devices are available to preserve specific components like cfRNA, microRNA, cfDNA, and proteins for extended periods at room temperature. (Source: Norgen Biotek Urine & Stool Sample Preservation and (https://norgenbiotek.com/category/stool))
