Library Preparation Using FFPE-Derived Tumor DNA for High-Throughput Hybridization-Based Targeted or Exome Sequencing

Area of Science:

• Oncology
• Genomics
• Molecular Biology

Background:

• Next-generation sequencing (NGS) is transforming oncology by enabling tumor genome profiling for diagnostic and therapeutic insights.
• Clinical laboratories increasingly use NGS, necessitating robust methods for analyzing tumor specimens.
• Fixed tumor tissue blocks are common clinical specimens requiring specialized handling for DNA isolation.

Purpose of the Study:

• To provide a detailed, step-by-step protocol for preparing DNA libraries from fixed tumor tissues.
• To outline critical precautions for handling clinical specimens to ensure DNA suitability for sequencing.
• To guide the application of hybridization-based capture methods for targeted genomic region enrichment.

Main Methods:

• DNA isolation from fixed tumor tissue blocks.
• DNA fragmentation and adapter ligation with barcoding for sample identification.
• Hybridization-based capture using multiplexed biotinylated probes for targeted regions.
• Washing to remove uncaptured fragments and low-cycle amplification for library preparation.
• Sequencing library preparation specifically for the Illumina platform.

Main Results:

• A comprehensive protocol for generating sequencing-ready DNA libraries from challenging fixed tissue specimens.
• Identification of key precautions crucial for successful DNA isolation and library preparation from clinical samples.
• Demonstration of a hybridization-capture method for enriching specific genomic regions of interest.

Conclusions:

• Standardized library preparation protocols are vital for reliable NGS in clinical oncology.
• Careful specimen handling and optimized protocols ensure high-quality DNA for accurate tumor profiling.
• This method facilitates the use of fixed tissue for targeted genomic analysis, advancing personalized cancer treatment.