Full Workflow for NGS Library Preparation, QC, and Instrument Loading

Convert DNA or RNA samples into sequencable libraries with correct fragment distribution, adapters, indexes, and quantitative results.

Experimental Objective

To convert DNA or RNA samples into sequencable libraries with correct fragment distribution, adapters, indexes, and quantitative results.

Scope and Experimental Requirements

  • Sample: Genomic DNA
  • Sample: cfDNA
  • Sample: Total RNA or mRNA
  • Sample: Amplicons and enriched products
  • Difficulty and Time: Advanced, approximately 1–3 days
  • Safety: Clinical or environmental samples should be handled according to approved biosafety procedures; pre- and post-amplification areas must be strictly separated to control contamination.

Standard Workflow

  1. Confirm sample quality and input amount
  2. Perform fragmentation or target enrichment as per application
  3. Perform end repair, A-tailing, and adapter ligation
  4. Magnetic bead purification or size selection
  5. Limited cycle amplification to avoid overamplification
  6. Determine library concentration and fragment distribution
  7. Verify index compatibility and equimolar pooling
  8. Complete pre-sequencing denaturation, dilution, and batch record

Equipment, Reagents, and Consumables

  • Equipment: PCR cycler, magnetic stand and automated liquid handling platform (as needed), fluorometer, fragment analyzer or electrophoresis equipment
  • Reagents: Fragmentation and end repair reagents, adapters and indexes, high-fidelity amplification master mix, magnetic bead purification and size selection reagents, library quantification standards
  • Consumables: Low-binding PCR plates, filtered pipette tips, plate seals, nuclease-free centrifuge tubes

Essential Controls and QC

  • Negative library control
  • Positive reference sample
  • Unique dual indexing strategy
  • In-batch quantification and fragment standards
  • Negative library should have no significant product; library concentration should meet platform requirements; main fragment peak and distribution should conform to design; no significant adapter dimers; indexes should not conflict and sample sheet should be traceable.

Key Parameters and Result Interpretation

Input amount, fragmentation intensity, adapter ratio, bead ratio, PCR cycle number, index uniqueness, library quantification method, and pooling strategy are core variables.

Pre-sequencing QC cannot replace post-sequencing quality assessment; library performance should be evaluated in conjunction with read count, Q30, alignment rate, duplication rate, insert size, and coverage uniformity.

Common Issues

If yield is low, check input and ligation efficiency; if adapter dimers are high, adjust adapter or bead ratio; if libraries are overamplified, reduce PCR cycles; if pooling is uneven, use appropriate quantification methods and recalculate molarity.

Product BOM Entry

Submit product and technical inquiry for this experiment

For Research Use Only: This workflow is for research experiment design and product selection only; specific parameters, compatibility, specifications, pricing, and delivery are subject to project evaluation and formal quotation.