Pericarp DNA Extraction via Enzymatic Tissue Separation

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Solution Overview

Problem

Conventional methods for isolating pericarp tissue from seeds fail to produce high-quality, pure maternally-derived DNA suitable for genetic applications, as they often result in contamination from paternal DNA, which is not acceptable for genetic analysis and breeding purposes.

Innovation Solution

A method involving soaking seeds in hydrogen peroxide (H2O2) followed by enzymatic treatment with Pronase to separate pericarp from other seed tissues, and subsequent DNA extraction using Qiagen MagAttract DNA extraction robotic platform to achieve high-purity maternal DNA.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional wet-milling or dry-milling methods are used to separate pericarp from seed tissues, then pericarp can be isolated, but the resulting DNA contains contamination from paternal DNA and is unsuitable for genetic analysis

Engineering Contradiction:
ImproveDNA purityVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The pericarp is divided into three distinct layers (exocarp, mesocarp, endocarp), and the invention specifically targets the inner pericarp layer for DNA extraction. This segmentation allows selective isolation of maternal tissue while leaving paternal tissues (aleurone, endosperm, germ) behind, achieving high DNA purity through targeted tissue separation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts and removes the inner pericarp layer from the seed structure using a specific enzymatic treatment protocol. By taking out only the pericarp layer and discarding the rest of the seed tissues, the method achieves pure maternal DNA isolation without requiring complete seed degradation or complex multi-step separation processes

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If pericarp tissue is isolated using conventional methods, then pericarp can be obtained, but the DNA extracted is contaminated with paternal DNA and cannot be used for maternal lineage analysis

Engineering Contradiction:
Improvematernal lineage analysis accuracyVSAvoidpaternal DNA contamination
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The invention applies local quality by focusing the DNA extraction on a specific local region (the inner pericarp layer) that is known to be maternally derived. By concentrating the extraction effort on this specific tissue region with distinct morphological and biochemical properties, the method achieves pure maternal DNA without contamination from paternal tissues

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses an intermediary enzymatic treatment protocol as a mediator between the pericarp tissue and the DNA extraction process. This intermediary treatment selectively degrades paternal tissues while preserving the pericarp structure, allowing clean separation and extraction of maternal DNA through a controlled biochemical intermediary step

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If complete seed tissue degradation is performed to isolate pericarp, then pericarp can be separated, but the process becomes complex and time-consuming

Engineering Contradiction:
Improvepericarp separation purityVSAvoidextraction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention applies partial action by performing only the necessary enzymatic treatment to separate the pericarp from the seed coat, rather than completely degrading all seed tissues. This partial enzymatic action is sufficient to achieve clean pericarp separation and DNA extraction, significantly reducing the time required compared to complete seed degradation methods

Inventive Principle:
Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method effectively isolates high-purity maternal pericarp DNA, ensuring its suitability for PCR-based genetic analysis and plant breeding applications by minimizing paternal DNA contamination, allowing for accurate maternal lineage analysis and breeding decisions.

Implementation Method 1

soaking seeds in hydrogen peroxide (H2O2)

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

enzymatic treatment with Pronase

Methodology Applied
Scientific EffectEnzyme: Enzyme

Data Source

PatentUS9416394B2Pericarp DNA extraction and matrilineage determination
Publication Date: 2016.08.16 AGRIGENETICS INC

AI summary

Methods for separating pericarp tissue from surrounding tissues in grain are provided. Included are methods for isolation of high-purity pericarp DNA from a grain plant that reflects the genotype of the maternal parent of the grain plant, such that the isolated DNA may be used in a PCR-based genotyping assay.