Single-Cell PCR Amplification Without Purification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current DNA analysis methods, particularly real-time PCR, face challenges in efficiently analyzing DNA from a small number of cells due to time-consuming purification steps and potential material loss, which complicates the workflow and reduces throughput.

Innovation Solution

A method involving direct amplification of single copy DNA targets from a single living cell using a microtiter plate with a dry composition of PCR primers, thermostable DNA polymerase, and dNTPs, where the cell is lysed and amplified within the same vessel without an intermediate purification step, using a PCR reaction buffer that is at least twice the volume of the cell sample, and incubated at 90°C for thermal activation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional DNA isolation and purification procedures are performed before PCR amplification, then PCR amplification quality is improved, but analysis time is increased and material loss occurs

Engineering Contradiction:
ImprovePCR amplification qualityVSAvoidanalysis time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent combines cell lysis and PCR amplification into a single reaction vessel and continuous process. The lysis buffer components are integrated directly into the PCR reaction mixture, eliminating the need for separate purification steps. This merging of steps allows DNA to be released from cells and immediately amplified without intermediate handling, thereby reducing analysis time while maintaining amplification quality through optimized buffer composition.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent incorporates all necessary lysis buffer components (detergents, proteases, and other cell disruption agents) into the PCR reaction mixture before the amplification process begins. This preliminary inclusion of lysis reagents ensures that cell breakdown and DNA release occur concurrently with the initial PCR cycles, eliminating the need for subsequent purification steps and reducing overall analysis time.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If traditional DNA isolation and purification procedures are performed before PCR amplification, then PCR amplification quality is improved, but workflow complexity is increased

Engineering Contradiction:
ImprovePCR amplification qualityVSAvoidworkflow complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple workflow steps (cell lysis, DNA release, and PCR amplification) into a single integrated protocol using one reaction vessel. The lysis buffer is pre-mixed with PCR reagents, eliminating the need for separate purification apparatus and intermediate transfer steps, thereby simplifying the overall workflow while maintaining amplification quality through careful reagent formulation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reaction buffer system serves multiple functions simultaneously: it acts as both the lysis buffer for cell disruption and the PCR reaction buffer for amplification. This multi-functional buffer composition includes detergents for membrane dissolution, proteases for protein degradation, and all necessary PCR components (polymerase, dNTPs, primers), eliminating the need for separate reagent systems and simplifying the workflow.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If traditional DNA isolation and purification procedures are performed before PCR amplification, then PCR amplification quality is improved, but material loss is increased

Engineering Contradiction:
ImprovePCR amplification qualityVSAvoidmaterial loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent combines cell lysis and PCR amplification in a single vessel without intermediate purification steps. This eliminates material loss associated with transfer operations, filtration, and column-based purification. The DNA remains in the reaction mixture throughout, ensuring maximum recovery of starting material while maintaining amplification quality through optimized buffer composition that prevents inhibition.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and removes the need for intermediate purification steps entirely from the workflow. By designing a lysis buffer that is compatible with PCR amplification, the method eliminates the extraction and purification phase that traditionally causes material loss, allowing direct progression from cell lysis to amplification with minimal handling and maximum DNA recovery.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If cell lysis and PCR amplification are performed in separate vessels with intermediate purification, then PCR amplification quality is improved, but the number of操作步骤 is increased

Engineering Contradiction:
ImprovePCR amplification qualityVSAvoidthroughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges cell lysis and PCR amplification into a single continuous process in one reaction vessel. The lysis buffer components are integrated into the PCR mixture, allowing cell disruption and DNA amplification to occur sequentially without interruption or intermediate purification. This reduces the number of操作步骤 from multiple discrete steps to a streamlined single-vessel protocol, thereby increasing throughput while maintaining amplification quality through optimized reagent formulation.

Inventive Principle:
Principle #5Merging (Combining)

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

This approach enables efficient, high-throughput, and simplified DNA analysis by allowing direct PCR amplification from a single cell without prior lysis or purification, maintaining sensitivity and specificity for single copy gene analysis, even with low starting material.

Implementation Method 1

incubating said vessel for at least 30 seconds at at least 90°C, thereby thermally activating the thermostable DNA polymerase

Methodology Applied
Scientific EffectThermal activation: Heating

Implementation Method 2

incubating said vessel for at least 30 seconds at at least 90°C, thereby thermally activating the thermostable DNA polymerase and lysing the cell

Methodology Applied
Scientific EffectThermal lysis: Heating

Data Source

PatentEP2625285B1Method for cell lysis and PCR within the same reaction vessel
Publication Date: 2020.04.29 ROCHE DIAGNOSTICS GMBH

AI summary

The present invention in general provides a method for amplification of a target DNA, comprising the steps of (i) transfering a liquid with a first volume comprising at least one or more living cells into a vessel (ii) adding to said vessel a PCR reaction buffer with a second volume, whereas said second volume is at least 2x as large as said first volume (iii) lysing said at least one or more living cells within said vessel by means of incubation for at least 1 Minute at at least 90°C, and (iv) amplifying said target by means of a polymerase chain reaction without performance of an intermediate purification step.