Why pre-screen DNA sequencing specialists before the interview
The expensive mistakes happen before the instrument starts. A contaminated library, an index collision or a poor quantification wastes a flow cell and a week, and the fault is rarely obvious in the output. Specialists worth hiring have diagnosed a failed run properly rather than repeating it and hoping. A short screen asks about a run that failed and what the cause turned out to be.
What actually matters when screening DNA Sequencing Specialist candidates
- 01
Technique and experimental design
Probe hands-on command of library prep and platforms: Illumina NovaSeq or NextSeq, Oxford Nanopore, PacBio HiFi, plus input QC via Qubit, TapeStation, and index selection for pooling.
- 02
Results that went somewhere
Ask which sequencing runs fed real deliverables: clinical variant reports, published assemblies, validated NIPT or oncology panels, or a submitted assay with turnaround time figures.
- 03
Troubleshooting and reproducibility
Test troubleshooting of failed runs: low cluster density, index hopping, adapter dimer contamination, flow cell errors, and how they restored reproducibility across batches and lots.
- 04
Documentation and collaboration
Check documentation discipline: batch records, LIMS entries, run metadata, CLIA or ISO 15189 traceability, and how they hand pipelines to bioinformatics colleagues.
Pre-screening questions to ask DNA Sequencing Specialist candidates
12 questions grouped by what they test. Ask the same set in every screen and score answers on a consistent scale, or send them as an async video screen and compare answers side by side.
Platforms they ran
3 questions01What experience do you have with next-generation sequencing technologies?
Listen forInstruments operated by them with run types and throughput stated, not samples sent to a facility.
Sequencing described as ordering a service, or platforms named without hands-on operation.
02Can you describe your familiarity with different sequencing instruments?
Listen forPlatform strengths and error profiles compared, with the choice justified for a particular application.
Platforms treated as interchangeable, or error profiles not understood for long read technologies.
03What experience do you have with Sanger sequencing?
Listen forUsed appropriately for verification, with trace quality read directly rather than trusted automatically.
Sanger dismissed as outdated, or base calls accepted without inspecting the trace.
Prep is disciplined
3 questions04What protocols do you follow for sample preparation?
Listen forQuantification and fragment size checked at each stage, with input quality assessed before starting.
Libraries pooled without quantification, or degraded input processed without adjusting the protocol.
05What steps do you take to prevent contamination in your workflow?
Listen forPhysical separation of pre and post amplification work, with dedicated equipment and negative controls.
Amplified product handled in the preparation area, or negative controls not run routinely.
06Can you describe optimising a protocol for a difficult sample?
Listen forA specific low input or degraded sample, with the changes made and their effect on the result.
Standard protocol applied regardless of sample quality, or optimisation attempted without controls.
Diagnoses a bad run
3 questions07How do you troubleshoot common problems during the sequencing process?
Listen forRun metrics read to separate a preparation fault from an instrument fault before repeating anything.
Failed runs repeated without diagnosis, or every problem attributed to the instrument.
08How do you ensure the accuracy and quality of your sequencing results?
Listen forQuality thresholds set in advance, with controls included and results rejected when metrics fail.
Marginal runs accepted because of deadlines, or quality assessed only after analysis looked odd.
09What approaches do you use to handle sequencing errors and discrepancies?
Listen forError profiles understood per platform, with independent confirmation used for important variant calls.
Variant calls reported without confirmation, or systematic platform errors treated as real variation.
Knows what data supports
3 questions10What bioinformatics tools do you commonly use for analysing sequencing data?
Listen forStandard tools used with their parameters understood, rather than pipelines run at default settings.
Pipelines run without understanding the steps, or parameters never adjusted for the application.
11Can you explain the importance of read length and depth in sequencing experiments?
Listen forDepth and read length chosen for the question, with the limits of low coverage clearly understood.
Coverage chosen by budget alone, or conclusions drawn from depth that cannot support them.
12What measures do you take to ensure data security and privacy in your work?
Listen forHuman sequence treated as identifying, with consent scope and access controls respected throughout.
Human data treated as anonymous, or consent limits on secondary use not checked.
How to score responses
Score every candidate on the same four criteria immediately after the screen. At this stage you are shortlisting for panel interviews, not making the final call.
Technique and experimental design
35%5Names platforms and chemistries run personally, explains multiplexing choices, coverage targets, and read length trade-offs for WGS versus amplicon panels.
Results that went somewhere
25%5Cites specific runs and downstream outcomes, including sample throughput per week, Q30 rates, and how data reached clinicians or collaborators.
Troubleshooting and reproducibility
25%5Walks through a specific run failure, the diagnostic steps taken, root cause found, and the control or SOP change that prevented recurrence.
Documentation and collaboration
15%5Describes maintained SOPs and LIMS records auditors accepted, plus concrete handoffs of FASTQ and QC metrics to analysis teams.
The expensive mistakes happen before the instrument starts. A one-way video screen asks about the run that failed.
Try it on HirevireScreening FAQ
Process basics
How long should a pre-screening round for this role take?
Fifteen minutes across eight to ten questions, answered async. Enough to establish platforms they ran, test their preparation and contamination discipline, and hear how they diagnose failures.
How much analysis should I expect from this role?
Enough to judge whether data is usable: quality metrics, duplication and coverage. Deep analysis usually sits with a bioinformatician, but a specialist who cannot read run metrics is limited.
Evaluating answers
What is the strongest signal when screening this role?
A failed run they diagnosed. Specialists with real bench time trace the cause back to a preparation step. Anyone who has only repeated failed runs has not learned from any of them.
How do I judge their contamination control?
Ask how they separate pre and post amplification work. Real answers describe physical separation and dedicated equipment. Anyone treating it casually will contaminate a whole batch eventually.
Go deeper on this role
Sanat has been hiring since 2012 and watching the recruitment industry change up close ever since, and turned that screening process into Hirevire's video screening platform. LinkedIn
