Single-Cell Transcriptome Analysis With Split-Pool Compound Barcodes
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Solution Overview
Problem
Existing methods for whole transcriptome analysis in single cells require physical isolation of cells and involve inefficient ligation steps, which are not suitable for detecting rare nucleic acid targets.
Innovation Solution
A method utilizing a split-pool process with reverse transcriptase to assemble compound barcodes on nucleic acid targets in individual cells, using oligonucleotide primers and barcode subunits, and extending these with nucleic acid polymerases to form unique cell-specific barcodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ligation steps are used to assemble barcodes on nucleic acid targets, then barcode assembly can be achieved, but the process efficiency is low and additional reagents are required
Solution Approach 1:
The patent replaces the mechanical ligation process with a biochemical polymerase extension process. Instead of using ligase enzymes to join barcode subunits, the invention uses polymerase enzymes to synthesize barcodes in situ on the nucleic acid targets during reverse transcription or amplification, eliminating the need for separate ligation steps and reducing process complexity
Solution Approach 2:
The barcode assembly process is integrated into the existing reverse transcription or PCR amplification process. The polymerase enzyme simultaneously performs its primary function of copying the target nucleic acid and the secondary function of assembling the barcode sequence, making the system self-sufficient and eliminating the need for additional reagents and steps
2Measurement precision
If physical isolation of individual cells is performed, then single cell analysis can be conducted, but the process becomes more complex and time-consuming
Solution Approach 1:
The patent combines multiple functions into a single workflow: cell lysis, target nucleic acid release, reverse transcription, and barcode assembly all occur in the same reaction vessel without physical cell isolation. This merging of steps eliminates time-consuming cell separation procedures while maintaining single-cell resolution through unique barcode assignment to each cell's target molecules
Solution Approach 2:
The reverse transcription or amplification reaction serves multiple purposes simultaneously: it copies the target nucleic acid for detection, assembles the cell-specific barcode, and enables subsequent high-throughput sequencing. This multi-functionality eliminates the need for separate cell isolation and barcoding steps
3Reliability
If ligation steps are used for barcode assembly, then barcodes can be attached to targets, but the method is less efficient for rare nucleic acid targets
Solution Approach 1:
The patent replaces the inefficient ligation mechanism with a more reliable polymerase extension mechanism that is better suited for rare targets. The polymerase can efficiently synthesize barcodes even when target molecules are scarce, as the reaction is driven by the polymerase's inherent ability to extend primers rather than by the slower ligation process
Solution Approach 2:
The barcode sequence is prepared and integrated into the primer or template before the reverse transcription or amplification begins. This preliminary preparation ensures that when rare target molecules are present, the barcode assembly can proceed immediately without requiring separate ligation steps, thereby improving detection efficiency and reliability
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
Enables efficient detection of multiple nucleic acid targets in individual cells without the need for cell isolation, improving the robustness and efficiency of barcode assembly.
Implementation Method 1
A unique property of the reverse transcriptase enzyme is employed to copy the barcode subunits and assemble a compound barcode
Implementation Method 2
contacting the plurality of cells in a sample with an oligonucleotide primer for each target nucleic acid in the presence of a nucleic acid polymerase to extend the oligonucleotide primer
Data Source
AI summary
The invention is a method of single cell transcriptome analysis. The method comprises detecting multiple transcripts in each individual cell of the plurality of cells by barcoding the transcripts with a cell-specific compound barcode formed using a DNA polymerase and a terminal transferase, optionally in a single enzyme such as a reverse transcriptase.