WES Probes: Complete Guide to Whole Exome Sequencing Probe Panels for Clinical and Research Applications

Whole exome sequencing (WES) has established itself as the gold standard for identifying disease-causing coding variants in clinical genetics and oncology. At the core of every WES workflow are exome capture probes — the engineered nucleic acid sequences that selectively enrich the ~1.5% of the human genome that encodes proteins.

The choice of WES probe panel determines everything downstream: which exonic regions are captured, how uniformly they are sequenced, how much data is needed to reach clinically actionable depth, and which variant types can be reliably detected. This guide provides a comprehensive overview of WES probe technology, compares Dynegene's three exome probe panels, and maps each to its optimal clinical application.

What Is Whole Exome Sequencing?

The Exome: 1.5% of the Genome, ~85% of Disease-Causing Mutations

The human genome contains approximately 3 billion base pairs, but only about 1.5% — roughly 30 million bases — encodes proteins. This protein-coding fraction is called the exome. Despite its small size, the exome harbors an estimated 85% of disease-causing mutations identified to date. WES focuses sequencing resources on this information-dense fraction, making it far more cost-effective than whole genome sequencing (WGS) for most clinical applications.

WES vs WGS: A Cost-Effectiveness Comparison

Factor	WES	WGS
Target size	~35–46 Mb (exome)	~3,000 Mb (whole genome)
Sequencing data needed	10–15G (100–200x depth)	90–120G (30x depth)
Cost per sample	Lower	Higher
Coding variant detection	✓ Excellent	✓ Excellent
Structural variants	Limited	✓ Comprehensive
Non-coding variants	✗ Not covered	✓ Covered
Turnaround time	Faster (less data)	Slower (more data)
Best for	Genetic disease, tumor profiling	Complete genomic characterization

WES is the preferred approach when your primary objective is to identify mutations in protein-coding genes — the regions most likely to cause genetic disease, drive cancer, or predict drug response.

How WES Probes Work: The Hybridization Capture Workflow

Step 1: Library Preparation

Genomic DNA is fragmented (enzymatically or mechanically) and ligated with sequencing adapters using a DNA Library Preparation Kit. Dynegene's Fragmentation Reagent provides enzymatic fragmentation for consistent fragment size distribution, and the QuarPro Superfast T4 DNA Ligase enables rapid adapter ligation.

Step 2: Hybridization Capture

The prepared library is denatured and hybridized with biotinylated WES probes. The probes bind to their complementary exonic target sequences, forming probe-target duplexes. Dynegene supports three hybridization protocols:

• Ultra-fast hybridization: As quick as 30 minutes
• Rapid hybridization: 1 hour — balanced performance and throughput
• Overnight hybridization: 12–16 hours — maximum capture efficiency

Step 3: Target Enrichment

Streptavidin magnetic beads capture the biotinylated probe-target complexes. Off-target sequences are removed through stringent washes, leaving only the enriched exomic library.

Step 4: Post-Capture Amplification and Sequencing

The enriched library undergoes PCR amplification, quality control, and is sequenced on an NGS platform. Dynegene's QuarStar 4.0 panels have been validated on the MGI sequencing platform (T7), among others.

Dynegene's WES Probe Portfolio: Three Panels for Every Application

Panel 1: QuarStar Human All Exon Probes 4.0 — Standard Version

Best for: Genetic disease testing, population genetics, baseline WES

Specification	Detail
Probe chemistry	Double-stranded DNA
Genome coverage	~35.5 Mb
Database design	Refseq / CCDS / GENCODE
Data requirement	~10G for ~100x effective depth
Hybridization	Rapid (1 hr) and overnight; single-plex and multiplex
Customization	Spike-in probes for additional targets
Product page	QuarStar 4.0 Standard

The QuarStar Standard is Dynegene's core WES panel. Key advantages:

• Excellent performance — Outstanding on-target rate and uniformity
• Cost advantage — Requires less sequencing data to achieve the same target depth
• Flexible combination — Spike-in sub-panels adapt to different testing requirements; up to 4.35 million oligos per chip enables rapid customization
• Broad compatibility — Rapid and overnight hybridization; supports multiplexed sample hybridization

Panel 2: QuarStar Human All Exon Probes 4.0 — Tumor Version

Best for: Clinical oncology, precision cancer diagnosis, comprehensive tumor profiling

Specification	Detail
Probe chemistry	Double-stranded DNA
Genome coverage	~46 Mb
Catalog number	NX3009
Additional targets	1,000+ tumor genes, fusions, MSI, HRD (23,157 SNPs), HLA
Design technology	AI algorithm-based probe design + Boosting strategies
Hybridization	Ultra-fast (30 min), rapid (1 hr), overnight
Compatible reagents	QuarHyb Super DNA (NC1009, rapid), QuarHyb DNA Plus 3 (NC1018, overnight)
Product page	QuarStar 4.0 Tumor

The Tumor version's defining innovation is differential sequencing depth:

Region	Average Effective Depth	Clinical Significance
General gene exons	>150x (~200x)	Germline variant detection
Tumor-related genes (1,000+)	>450x (~500x)	Somatic mutation detection
Hotspot regions	>650x (~900x)	Low-frequency driver mutations

Built-in Oncology Biomarker Detection:

• Gene Fusions — ALK ~900x, ROS1 ~800x, RET ~1,000x, NTRK1 ~1,000x; detection validated to 2.08% AF (ddPCR-confirmed)
• HRD — 23,157 WGS-verified, GC-balanced heterozygous SNPs for LOH/TAI/LST genomic scar detection
• MSI — Integrated microsatellite markers for MSI-H/MSS determination
• HLA — Coverage for immunotherapy-relevant typing
• TMB — Comprehensive exonic coverage for accurate TMB calculation

Panel 3: QuarXeq Human All Exon Probes 3.0

Best for: Maximum sensitivity WES, FFPE samples, genetic disease + precision oncology

Specification	Detail
Probe chemistry	Double-stranded RNA
Database design	Refseq / CCDS / GENCODE
Special coverage	TERT promoter, challenging genomic regions
Hybridization	Rapid and overnight; single-plex and multiple-plex
Product page	QuarXeq 3.0

The QuarXeq 3.0 exploits the thermodynamic advantage of RNA-RNA hybrids (stronger than RNA-DNA or DNA-DNA):

• Enhanced sensitivity — Superior target capture from degraded FFPE or low-input materials
• Dual-strand capture — dsRNA probe technology captures both sense and antisense strands simultaneously
• TERT promoter coverage — Explicitly designed to include this clinically significant challenging region

Choosing the Right WES Panel: Decision Matrix

Your Need	Recommended Panel	Why
Genetic disease screening (germline)	QuarStar Human All Exon Probes 4.0 (Heredity)	Cost-effective, more comprehensive coverage, more stable performance, ~41.05 Mb, ~250x
Comprehensive tumor profiling (somatic)	QuarStar 4.0 Tumor	Differential depth, 1,000+ tumor genes, fusions, HRD, MSI
High-throughput clinical lab (max speed)	QuarStar 4.0 Tumor	Ultra-fast 30-min hybridization
Immunotherapy biomarkers (TMB, HLA, MSI)	QuarStar 4.0 Tumor	Integrated TMB + HLA + MSI in one capture
Carrier screening / population studies	QuarStar 4.0 Standard	Economical, high uniformity

Clinical Applications in Detail

Genetic Disease Diagnostics

WES is the first-line genetic test for undiagnosed rare diseases, achieving diagnostic yields of 25–40% in clinical practice. The QuarStar Standard panel provides the most cost-effective approach for germline WES with comprehensive CDS coverage.

Precision Oncology

The QuarStar Tumor panel enables a single-capture, multi-biomarker approach:

1. Somatic mutation detection in 1,000+ cancer genes at >450x depth
2. Hotspot variant calling at >650x for treatment-selecting mutations
3. Gene fusion detection with validated intronic coverage for ALK, ROS1, RET, NTRK1
4. TMB + MSI + HRD + HLA — all from one WES capture

This integrated approach replaces multiple separate tests, reducing total cost, turnaround time, and sample consumption.

Applications in Molecular Diagnostics

Dynegene's WES probes support the full spectrum of molecular diagnostic applications: HRD, MRD, MSI, and TMB.

Complete WES Workflow Products

Hybridization Reagent Kits

Product	Catalog	Mode
QuarHyb Super DNA Reagent Kit	NC1009	Rapid
QuarHyb DNA Plus 3 Reagent Kit	NC1018	Overnight
QuarHyb DNA Plus 2 Reagent Kit	—	Versatile
QuarHyb One Reagent Kit	—	Streamlined
QuarHyb Super Reagent Kit Pro	—	RNA probes

Library Preparation and Accessories

Product	Function
DNA Library Preparation Kit	Fragment, end-repair, ligate
Fragmentation Reagent	Enzymatic DNA fragmentation
QuarPro Superfast T4 DNA Ligase	Rapid adapter ligation
Streptavidin Magnetic Beads	Target enrichment pulldown
Dynegene Adapter Family	Sequencing adapters
Dynegene Blocker Family	Hybridization blockers
iQuars50 NGS Prep System	Automated sample preparation

Frequently Asked Questions

What are WES probes and how do they work?

WES probes are biotinylated nucleic acid sequences that selectively capture protein-coding exons (~1.5% of the genome, harboring ~85% of disease-causing mutations). During hybridization, probes bind to target exonic sequences in a DNA library; complexes are pulled down with streptavidin magnetic beads, enriching the exome for sequencing. Dynegene offers DNA-based (QuarStar, ~35.5–46 Mb) and RNA-based (QuarXeq) WES panels.

What is the difference between WES and WGS?

WES captures only protein-coding exons (10–15G data for 100–200x depth), while WGS sequences the entire genome (90–120G for 30x). WES is more cost-effective for coding variant detection — the primary goal in genetic disease and tumor profiling. WGS is preferred when structural variants or non-coding regions are needed.

What WES probe panels does Dynegene offer?

Three panels: QuarStar Standard (DNA, ~35.5 Mb, genetic disease testing and precision cancer diagnosis), QuarStar Tumor (DNA, ~46 Mb, NX3009, AI-designed, differential depth, integrated oncology biomarkers), QuarStar Heredity (DNA, ~41.05 Mb, ~250x, cost-effective with more comprehensive coverage and more stable performance), and QuarXeq 3.0 (RNA, TERT promoter, enhanced sensitivity). All support rapid and overnight hybridization with single-plex and multiplex workflows.