Algorithm to evaluate efficacy of detecting cellular variants in a heterogeneous cell population
OwnerThuraiayah Vinayagamoorthyinventor
Life of this patent
Estimating the term…
Abstract
Somatic mutations are associated with cancer progression and treatment using targeted therapies. Somatic mutations are not inherited and could be present at low concentrations in biopsy samples. Hence, there is a need for more sensitive assays to detect these changes in the presence of heterogeneous cell populations. The efficacy of such detection is determined by two factors; the ability to detect a minimum number of copies of the target mutation in the sample (Lower limit of detection), and the ratio of target mutation to that of wild-type in the sample (Tumor content). A new algorithm Detection Index (DI) is formulated to evaluate the efficacy of detection for a molecular testing method.
Claims15
A method of comparing detection indices of two or more tests performed separately, each test comprises;
- (b) using a clinical specimen carrying cancer cells with heterozygous alleles for a somatic mutation, and
- (c) viewing in a microscopic field counting total number of cells and the total number of cancer cells, and
- dividing the total number of cancer cells by the total number of cells, generating the tumor content, and
- multiplying the tumor content by 100 to determine the percentage tumor content, and
- (d) extracting the total DNA from the clinical sample, and
- using spectrophotometer to determine the DNA concentration (ng/ul) of the DNA extract, and
- multiplying volume (ul) of DNA extract added to the reaction by the DNA concentration to determine the amount of DNA, and
- (e) adding up the volumes of reagents added to the reaction to determine the reaction volume (ul), and
- (e) calculating the number of copies of the mutant allele (MC) per milliliter by
- Amount
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- of
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- DNA
- ×
- 290
- ×
- %
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- tumor
-
- content
- Reaction
-
- volume
-
- (
- μ
-
- l
- )
- ×
- 100
- (f) calculating number of copies of wild type allele (WC) per milliliter by
- (
- Amount
-
- of
-
- DNA
- ×
- 290
- ×
- %
-
- tumor
-
- content
- )
- +
- [
- (
- Amount
-
- of
-
- DNA
- ×
- 290
- ×
- 100
- -
- %
-
- Tumor
-
- content
- )
- ×
- 2
- ]
- Reaction
-
- volume
- (
- μ
-
- l
- )
- ×
- 100
- and
- (g) determining the detection index by multiplying the inverse of (MC) and inverse of the ratio of (MC:WC), and
- the test with higher detection index is more sensitive in detecting the somatic mutation.
Dependencies are inferred from the claim text.