Single Cell Methylation Sequencing via Combinatorial Indexing
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Solution Overview
Problem
Current single-cell bisulfite sequencing methods lack scalability and are costly due to the need for new reagents for each cell, and no microfluidics systems have been deployed for this purpose.
Innovation Solution
The use of single-cell combinatorial indexing strategies combined with transposase-based adaptor incorporation allows for the processing of cells in bulk and the demultiplexing of single-cell output in silico, resulting in higher alignment rates and reduced sequencing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If single-cell deconvolution via parallel and isolated library generation is used, then single-cell resolution is achieved, but scalability is limited and costs increase linearly with each additional cell
Solution Approach 1:
The patent combines multiple single-cell library preparations into a single bulk reaction by pooling nuclei from multiple cells, adding combinatorial barcodes, and processing them together through transposase-based adaptor incorporation and bisulfite conversion, thereby achieving scalability while maintaining single-cell resolution through computational demultiplexing
Solution Approach 2:
The patent uses combinatorial barcode indexing to create unique molecular identifiers for each cell's genomic material, allowing parallel processing of many cells and subsequent computational separation of individual cell signals from the pooled data
2Measurement precision
If single-cell deconvolution via parallel and isolated library generation is used, then single-cell resolution is achieved, but reagent costs increase linearly for each additional cell
Solution Approach 1:
The patent merges reagent usage across multiple cells by performing bulk library preparation with shared reagents including transposase, adaptors, and bisulfite, thereby reducing per-cell reagent consumption while maintaining single-cell analytical resolution through barcode-based demultiplexing
Solution Approach 2:
The patent recovers and reuses common reagents across multiple cells in a pooled format, eliminating the need to consume fresh reagents for each individual cell preparation
3Manufacturing precision
If traditional single-cell library construction methods are used, then alignment rates are low (10-30%), but the methods are simpler to implement
Solution Approach 1:
The patent performs preliminary adaptor incorporation via transposase before bisulfite conversion, ensuring proper library structure is established early in the workflow, which significantly improves subsequent alignment rates while the added complexity is offset by streamlined downstream processing
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 more efficient library construction, higher alignment rates (~60%), and a significant reduction in sequencing costs, while maintaining the ability to demultiplex and analyze single-cell methylome profiles effectively.
Implementation Method 1
the methods provided herein make use of transposase-based adaptor incorporation which results in increased efficiency and much higher alignment rates over exiting methods
Implementation Method 2
DNA methylation can be probed at base pair resolution using the deaminating chemistry of sodium bisulfite treatment
Data Source
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AI summary
Provided herein are methods for preparing sequencing libraries for determining the methylation status of nucleic acids from a plurality of single cells. The present methods combine split-and-pool combinatorial indexing and bisulfite treatment techniques to characterize the methylation profiles of large numbers of single cells quickly, accurately and inexpensively.