Internal Standard Quantification
Internal Standard Quantification - Related Videos
09:18
Internal Standards
0 Views •
2023
Source: Laboratory of Dr. B. Jill Venton - University of Virginia The goal of many chemical analyses is a quantitative analysis, where the amount of a substance in a sample is determined. In order to accurately calculate the concentration of an unknown from a sample, careful sample preparation is key. Every time a sample is handled or transferred, some of the sample can be lost. There are strategies however, for minimizing sample loss. There are also strategies for coping with sample loss and...
01:30
Introduction to International Financial Reporting Standards (IFRS)
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2025
International Financial Reporting Standards (IFRS) are globally accepted accounting principles developed by the International Accounting Standards Board (IASB). IFRS aims to create consistency in financial reporting across countries, promoting comparability, transparency, and accountability in financial statements. This standardized approach simplifies reporting for multinational corporations and supports cross-border investment by reducing the complexity caused by varying national accounting...
10:50
Single-cell Gene Expression Profiling Using FACS and qPCR with Internal Standards
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Cited by 7 •
2017
We describe a method to sort single mammalian cells and to quantify the expression of up to 96 target genes of interest in each cell. This method includes the use of internal qPCR standards to enable the estimation of absolute transcript counts.
08:46
A Standardized Method for Measuring Internal Lung Surface Area via Mouse Pneumonectomy and Prosthesis Implantation
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Cited by 22 •
2017
Internal lung surface area (ISA) is a critical criterion for assessing lung morphology and physiology in lung diseases and injury-induced alveolar regeneration. We describe here a standardized method that can minimize the measurement bias for ISA in both lung pneumonectomy and prosthesis implantation mouse models.
02:00
Internal Energy
0 Views •
2020
The total of all possible kinds of energy present in a substance is called the internal energy (U), sometimes symbolized as E. Suppose a system with initial internal energy, Uinitial, undergoes a change in energy (transfer of work or heat), and the final internal energy of the system is Ufinal. Change in internal energy equals the difference between Ufinal and Uinitial. Although the values for Ufinal and Uinitial cannot be determined for a system, the first law of thermodynamics only...
FAQs
The ratio places the target signal in relation to a reference measured in the same sample. Variations caused by sample handling or instrument response can therefore influence both signals, reducing their effect on the calculated amount. This makes comparisons among biological samples more reliable than relying on the target signal alone.
Matching these stages helps the reference experience the same analytical conditions as the target compound. Their signals then reflect comparable effects from processing and measurement, which supports meaningful ratio calculations. This alignment is especially important when biological samples differ in composition or when several handling steps could affect the measured response.
A consistent amount provides a stable basis for comparing analyte signals across samples. Differences in the resulting ratios are then more closely associated with differences in target abundance rather than changes in how much reference was introduced. This supports precision when researchers assess biological conditions or compare experimental groups.
The workflow begins by adding a known, consistent amount of internal standard to each biological sample. The sample and reference then proceed through preparation, separation, and detection together. Researchers measure both signals, calculate their relationship, and use that ratio to determine the target amount. Keeping these conditions consistent supports valid comparisons.
Internal Standard Quantification can support measurements of metabolites, proteins, nucleic acids, and other biomolecules. The same general strategy links each target signal to a known reference signal, while the specific sample preparation, separation, and detection conditions can be suited to the molecule being studied. This makes the approach broadly relevant to biological analysis.
By improving precision across samples, the method helps researchers compare biological conditions and evaluate experimental changes. Quantitative results can also contribute to assay validation by showing whether the measurement procedure produces consistent, interpretable values. Its value lies not only in estimating target amounts, but also in strengthening comparisons among biological samples.