Sequencing Only Frequently Asked Questions


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General Questions

Sample Preparation

Order & Processing

General Questions


1. What type of premade libraries can I submit?

You can submit any Illumina®-compatible library for sequencing, such as libraries from genomic DNA for whole genome sequencing or RNA for transcriptome sequencing.


2. How do I prepare my libraries for sequencing?

You can use any Illumina-compatible library preparation kit.

3. What sequencing platforms and configurations are available?

See below. Minimum outputs are shown. Please contact us if your project requires a different platform or configuration.

  • MiSeq 2x150 bp → ~4.5 Gb Data Output, 10-15M Reads
  • MiSeq 2x250 bp → ~7.5 Gb Data Output, 10-15M Reads
  • NovaSeq/HiSeq 2x150 bp → 90-106 Gb Data Output, 300-350M Reads
  • HiSeq 2x250 bp → 75 Gb Data Output, 150M Reads

4. What does it mean to be a standard Illumina-compatible library?

Illumina-compatible libraries require four major components in their adapter sequences, found at the ends of each fragment, for paired-end sequencing:

  • Flow cell binding sites. Known as P5 or P7, they facilitate clustering of the DNA strands on the flow cell.
  • Sequencing primer binding sites. Labeled as Read 1 and Read 2, they are necessary to initiate sequencing at both ends of the fragment.
  • Index sequences. Often called i5 and i7, they act as barcodes to allow multiplexing (pooling) of samples. Libraries can be either single index (having one index sequencing) or dual index (having two index sequences), and each library to be pooled requires at least one unique index.
  • Index primer binding site(s). These are required to read the index sequences.

The composition of the adapter sequences depends on whether the library is single or dual indexed (see figure below). If any of the components are missing, heavily modified, or in the wrong configuration, sequencing may fail. If you have any questions regarding your library configuration, please contact us.

Single-Indexed Sequencing
Dual-Indexed Sequencing

5. Can you spike PhiX into my sequencing run?

Yes, please instruct our team what percentage of PhiX spike-in to use, and we’ll accommodate the request free of charge. We typically recommend ~10% PhiX spike-in for projects with low diversity libraries.


6. Can you perform data analysis for my sequencing-only project?

Yes, please indicate this on the quote request form.


7. What are your starting material requirements for premade libraries?

We request that each library or library pool be ≥15 nM, ≥20 µL, in water or EB buffer. If you cannot meet these requirements, please contact us for further details.


8. How do I ship my premade libraries to you?

We request that you ship your libraries overnight on dry ice directly to our NJ facility (address located in the quotation).


9. What QC is performed on the premade libraries?

We will run your libraries on the Agilent2100 Bioanalyzer to check the insert size and perform final quantification via qPCR prior to loading.


10. Can GENEWIZ de-multiplex my data?

We ask that you provide the index sequences in the Sample Submission Form prior to your sequencing run. GENEWIZ will provide the de-multiplexing free of charge. Alternatively, if no index sequences are provided, we will deliver the raw data and you can perform the de-multiplexing.


11. Can GENEWIZ perform de-multiplexing of “in-line” barcodes in sequencing reads?

Yes, we offer de-multiplexing of in-line barcodes in sequencing reads (not index reads). Please contact us for further details. Additional charges may apply.


12. Do you accept sequencing libraries with custom sequencing or index primers?

Yes, please contact us for further details.


13. How do I contact GENEWIZ for a technical consultation about my project?

GENEWIZ's NGS Team is composed of Ph.D. scientists who can help you optimize your project design and provide consultation. Contact the team directly at, toll-free at 877-436-3949 ext. 1, or directly at +1-908-222-0711 ext. 1.


14. Can you recommend the best data delivery option?

Yes, we can recommend the best data delivery option based on the platform and project details. Options include:

  • Secure File Transfer Protocol (SFTP)
  • Customer Cloud Account
  • Hard Drive (additional charges may apply)


15. What is the price for NGS?

Please submit a quote request to receiving accurate pricing information, as the cost depends on the details of the project.

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Sample Preparation


16. How should I prepare and send my samples?

  • Sample Type: Premade Sequencing Library
  • Recommended Amount: >15 nM, >20 µL
  • Buffer: Water, EB, or low TE (<0.1 mM EDTA)
  • Shipment Method: Dry ice


17. What happens if my samples do not meet your starting material requirements? 

Please contact us at or +1-877-436-3949 ext. 1.


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Order & Processing


18. How do I request a quote?

For a quick tutorial, watch the video below. Select the Sequencing Only icon.


19. How do I confirm a quote?

For a quick tutorial, watch the video below.


20. How do I submit the GENEWIZ sample form (to provide detailed information about my samples)?

For a quick tutorial, watch the video below. 


21. How can I monitor the progress of my project?

The status of your order, including an estimated date of delivery, can be viewed anytime through your GENEWIZ account. Visit the Order Summary page of your project to find the current order status.


22. How long do you hold samples?

We hold samples for 1 year after project completion. Please contact us if you would like samples retained for a longer period of time or shipped back to you.

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Have a specific question?

 Email |  Phone (1-877-GENEWIZ (436-3949), Ext. 1)



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