Before you buy, get written answers on four things: what you receive (files, coverage, reference build), what gets reported (variant types, classification, secondary findings), what happens to your data and sample (ownership, research use, deletion), and what it really costs and supports (accreditation, updates, support, fees).
The twelve questions below are provider-neutral. Use them on every company you consider, including ones we have affiliate relationships with.
What you receive
1. What coverage depth and which sequencing technology do you use?
Whole genome tests are usually sold by average read depth, with 30x the common clinical-style target. Lower depth is cheaper and can miss variants. Ask for the stated depth and whether the figure is an average or a guaranteed minimum. Our explainer on 30x coverage shows why it matters, and the long-read versus short-read guide covers what the technology can see.
2. Which raw files do I get, and can I download them?
The most important file questions are whether you get FASTQ (raw reads), BAM or CRAM (aligned reads) and VCF (variant calls), and whether they are included in the price. A report without files leaves you dependent on the company. Our FASTQ, BAM and VCF explainer describes each one.
3. Which reference genome build is my data aligned to?
Many third-party tools assume a specific build, such as GRCh37 or GRCh38, and break or mislead on the wrong one. Ask which build the files use and whether realignment is offered. We explain the mismatch problem in GRCh37 vs GRCh38.
What gets reported
4. Which variant types does the analysis cover?
Single-letter changes and small insertions or deletions are the baseline. Ask whether the pipeline also reports copy number changes, larger structural variants and mitochondrial DNA, or whether those are only present in the raw data. Our post on structural variants explains why this gap matters.
5. How are variants classified, and what happens to uncertain ones?
Reputable reports use a published framework such as the ACMG and AMP categories: pathogenic, likely pathogenic, uncertain, likely benign and benign. Ask whether uncertain results are shown, hidden or flagged, and who reviews them. Our guide to variants of uncertain significance explains why that choice matters.
6. Will I receive secondary findings, and can I opt out?
Some reports include findings unrelated to your reason for testing, usually from a medically actionable gene list. Ask whether this is on by default and whether you can decline before results arrive. We discuss the decision in secondary findings: opt in or opt out.
What happens to your data and sample
7. Who can use my data, and is research use opt-in or opt-out?
Read the research consent as a separate decision from buying the test. Ask whether data is shared with partners, whether it is identifiable or de-identified, and whether you can withdraw later. Our DNA data privacy comparison covers how providers have handled this.
8. Can I delete my data and have my sample destroyed?
Deleting an account and destroying a physical sample are often separate requests. Ask what each one removes, what the company must keep for legal reasons, and how long it takes. See can you really delete your DNA data and what happens to your saliva sample.
9. Where is my data stored, and what happens if the company is sold or fails?
Ask which country hosts the data, which privacy laws the company says it follows, and what its policy says about a sale or bankruptcy. The 2025 sale of 23andMe is a reminder that this is not a hypothetical. Our 23andMe timeline sets out what happened.
What it really costs and supports
10. Is the lab accredited, and can my doctor use the result?
Ask which laboratory runs the sample and what accreditation it holds, for example CLIA in the United States. Then ask whether the company states that results are for information only or suitable for clinical decisions. Even with accreditation, a finding that would change care is normally confirmed through your clinician. See DTC versus clinical-grade testing.
11. Will my results be updated, and for how long?
Sequence data stays fixed, but knowledge about variants keeps changing. Ask whether the company re-runs your file against updated databases, how often, and whether it is free or a paid add-on. We explain the stakes in why your genome needs reanalysis.
12. What is the total cost, turnaround and failure policy?
Ask for the all-in price including shipping, taxes and import charges if you live outside the seller's country, a realistic turnaround range, and what happens if the sample fails quality control. Support responsiveness varies widely between providers, so look for recent independent reviews rather than relying on the sales page. Our cost breakdown and international shipping guide cover the extras.
Get answers in writing. If a company will not say, in plain terms, whether you can download your files and delete your data, that is your answer to questions 2 and 8. Save the policy pages or support replies with the date, because policies change after acquisitions and updates.
Using the list
You do not need a perfect score. Decide which questions are deal-breakers for you. Most people end up with a short list: files included, clear deletion process, a named accredited lab and a research consent that is genuinely optional. Then compare providers on price. Our provider comparison and whole genome versus genotyping guide are good next reads.
Run these twelve questions on Dante Labs too
We are paid an affiliate commission by Dante Labs, so do not take our word for it. Ask it the same questions. In particular, check the current file formats included, the research consent options and the deletion process on its own pages before you buy.
Check Dante Labs → Code GENOME — 10% offAffiliate link. Consumer sequencing is not a clinical diagnostic. Confirm findings through your doctor.
Common questions
What is the most important thing to check before buying whole genome sequencing?
Whether you can download your raw data files and whether you can delete your data later. Those two answers tell you how much control you keep after the report is delivered.
Does a cheaper whole genome test mean lower quality?
Not automatically, but price often reflects sequencing depth, included files, report scope and support. Ask for the stated average coverage, which files are included and what is reported, then compare like with like.
Do I need a doctor to order whole genome sequencing?
Many consumer providers sell directly without a doctor's order, while clinical whole genome sequencing is ordered by a clinician. Consumer results that could change medical care should be confirmed through a clinical laboratory.
Should I worry about my DNA being used for research?
It is a personal choice. Check whether research use is opt-in or opt-out, whether data is de-identified, and whether you can withdraw later. Treat it as a separate consent from buying the test.
How do I compare providers fairly?
Use the same written questions for each one: coverage, files, reference build, variants reported, classification, secondary findings, data use, deletion, accreditation, updates and all-in cost. Save the answers with dates.
Sources and verification
This checklist is editorial guidance, not a set of verified provider facts. It names no prices or provider claims beyond what appears in our existing articles. The 23andMe sale reference is covered in our linked timeline. Confirm every answer on the provider's own current pages.
Medical disclaimer. GenomeTesting.org publishes educational content about genetics and consumer genomic testing. Nothing here is medical advice, a diagnosis, or a substitute for care from a qualified clinician or genetic counsellor. Decisions about testing, treatment, or interpreting your own results should be made with a healthcare professional who can see your full history.
Affiliate disclosure. Some links on this page are affiliate links. If you buy through them we may earn a commission at no extra cost to you. This never changes which products we recommend or what we say about them.