Tumor Fraction Estimation
Tumor Fraction Estimation - Related Videos
02:29
Pyruvate Assay for Estimation of Pyruvate Levels in Cellular Fractions of Worms
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2025
This video describes a colorimetric assay for quantitatively measuring pyruvate in the cellular fractions of Caenorhabditis elegans. Utilizing the hydrogen peroxide produced from the enzymatic reaction of pyruvate oxidase with cellular pyruvate, a chromogenic dye is oxidized to produce a colored product, measured using colorimetry to determine the pyruvate concentration.
07:55
The Optical Fractionator Technique to Estimate Cell Numbers in a Rat Model of Electroconvulsive Therapy
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Cited by 24 •
2017
Here, we present a stereological method, the optical fractionator, used to quantify the formation of new neurons, and their survival, in the rat hippocampus following electroconvulsive stimulation. When correctly implemented, the sensitivity and efficiency of stereological methods ensures accurate estimates with a fixed and predetermined precision.
08:19
Stereological Estimation of Dopaminergic Neuron Number in the Mouse Substantia Nigra Using the Optical Fractionator and Standard Microscopy Equipment
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Cited by 45 •
2017
This work presents a step-by-step protocol for the unbiased stereological estimation of dopaminergic neuronal cell numbers in the mouse substantia nigra using standard microscopy equipment (i.e., a light microscope, a motorized object table (x, y, z plane), and public domain software for digital image analysis.
10:09
Fractional Distillation
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2023
Source: Laboratory of Dr. Nicholas Leadbeater — University of Connecticut Distillation is perhaps the most common laboratory technique employed by chemists for the purification of organic liquids. Compounds in a mixture with different boiling points separate into individual components when the mixture is carefully distilled. The two main types of distillation are "simple distillation" and "fractional distillation", and both are widely used in organic chemistry laboratories. Simple distillation...
04:25
Preparation of Subcellular Fractions from Leukemic Cells: A Method to Generate Cellular and Nuclear Fractions from Leukemic Cells
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2023
This video describes the preparation of subcellular fractions from leukemic cells which is a method to generate cellular and nuclear fractions from leukemic cells. The nuclear and cytoplasmic fractions can be used for further downstream analysis.
FAQs
Tumor fraction changes the proportion of sequencing reads carrying a tumor-associated variant because tumor DNA is mixed with DNA from normal cells. As the normal component increases, the observed variant allele frequency can be reduced relative to the signal expected from tumor material alone. Accounting for this effect helps distinguish weak biological signals from apparent low-frequency findings.
Morphology provides visual evidence for which cells appear malignant, while cellularity indicates how densely cells are distributed within the sampled tissue. Considering both features helps assess whether a specimen contains enough recognizable tumor material and how much normal tissue may be contributing to the sample. This context strengthens interpretation of later molecular measurements.
Molecular signals provide an additional line of evidence when tissue morphology alone cannot fully resolve the mixture of malignant and normal cells. Comparing molecular findings with observed cellular features can support a more informed estimate and reveal whether sequencing results are consistent with the available tumor material. This combined view is especially relevant for interpreting mixed biological samples.
Analysts use the estimate to place observed sequencing findings in the context of sample purity, meaning the relative contribution of tumor and normal material. A variant detected in a mixed specimen may show a different allele frequency than it would in a tumor-enriched sample. Incorporating tumor fraction therefore improves interpretation and supports more reliable assessment of candidate variants.
Sample selection can take into account the amount of recognizable tumor, overall cellularity, and the expected strength of molecular signals. Specimens with substantial normal material may provide weaker or more difficult-to-interpret genomic findings. Estimation helps researchers compare available tissues and prioritize samples whose composition is suitable for the intended molecular analysis.
Tumor fraction provides composition context when researchers evaluate biomarkers or compare results across specimens. Differences in the proportion of malignant cells can alter molecular signals even when the underlying biological feature is similar. Considering that variation helps separate sample-composition effects from meaningful differences between tumors, improving comparisons in cancer research and molecular profiling studies.