Interview Questions to Ask a Lab Technician
For the lab manager, supervisor or PI hiring a laboratory technician, whether the bench is clinical, research or industrial. These interview questions to ask a lab technician open with what the candidate has run and how much of it was checked, then move through bench technique, records, quality control and the result that looks wrong, safety and samples, and the shifts and supervision that come with the job. Two are exercises, a dilution worked on paper and a pipette with a tube of water, because ten minutes of watching settles what an hour of talk cannot.
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The questions
Each question, and why to ask it
Background
What does your current lab test or study, and which tasks there are yours from start to finish?
Why ask it
Clinical, research and industrial labs share a job title and little else, so settle which one you are hearing about first. Then listen for work they owned outright, such as running the morning chemistry batch or keeping a cell line going, as opposed to steps they helped with.
Which instruments have you run yourself, and for each one, did you load samples, set up the run, or maintain it too?
Why ask it
Three levels hide behind 'I have used it': pressing start on a method someone else built, building the run, and keeping the machine healthy. Name the instrument that matters most on your bench and ask how they would take it from switched off to its first sample.
Which parts of this job have you already done, and which would be new to you?
Why ask it
Read the main duties aloud first, or hand over the posting. A candidate who sorts the list honestly into 'done for years', 'done a few times' and 'never' has given you a training plan, and tends to be more reliable than one who claims all of it.
On an ordinary day in that lab, how many samples or runs go through your hands, and who checks your work before it leaves the bench?
Why ask it
Twenty samples a day with every result reviewed and three hundred released on your own sign-off are different jobs, and a resume describes both in the same words. Give your own bench's numbers straight afterward. A big jump in either direction is manageable when both of you know about it before the first week.
What training, degree or certification do you hold, and is any of it still in progress or due for renewal?
Why ask it
What a technician has to hold depends on the kind of lab and where it is, so find out your own requirement before the interview and do not lean on the candidate's understanding of it. Someone who can give a renewal date without looking it up usually keeps track of other dates too.
From what you have read about us, what are this lab's results used for?
Why ask it
A candidate who looked will know whether you test patient samples, support a research group or release product, and what that does to the pace and to the cost of an error. For a research post, a glance at one recent paper is plenty: you are hiring careful hands, not a second PI. If they did not look, tell them now, because it frames every question that follows.
Which part of bench work would you be sorry to give up?
Why ask it
The answer sorts people in a way 'I like science' never does: for some it is the instrument that finally behaves, for some a rack of identical samples finished on time, for some the troubleshooting. Hold it against what your bench offers on most days, and say so if their favorite part is rare here.
Bench skills
Pick the technique you know best and talk me through it as if I had to do it tomorrow.
Why ask it
Someone who has done it a hundred times adds what no protocol spells out: what the pellet should look like, which step cannot be hurried, where beginners go wrong. A recital in the kit insert's order with nothing added suggests fewer repetitions than the resume implies.
How do you pipette small volumes accurately, and how do you know the pipette is still delivering what the dial says?
Why ask it
Pre-wetting the tip, a steady angle and speed, and choosing the pipette whose range suits the volume are the habits a trained hand mentions. The dial is the harder half: find out whether they have ever checked a pipette by weight, or know when theirs was last calibrated. If you can, hand one over with a tube of water and watch.
You need 500 milliliters of working solution from a stock that is ten times concentrated. Talk me through making it, including what goes on the bottle.
Why ask it
Put paper on the table and let them do it. The arithmetic is easy on purpose, fifty milliliters of stock made up to five hundred, so nerves do not decide the result. Watch whether the units are said aloud and whether the label gets contents, concentration, date and initials without a prompt.
Tell me about a standard curve or serial dilution you set up recently. How did you decide it was good enough to use?
Why ask it
A technician who understands the curve talks about the blank, the range the samples had to fall inside and how the points sat on the line. 'The software accepted it' is an answer about the software. Ask what they did with a sample that read above the top standard.
Have you worked with cell cultures, microbial cultures or anything else that has to stay sterile? How do you keep it clean?
Why ask it
Leave this out if nothing on your bench needs aseptic technique. Where it does, listen for the order of work in the cabinet, what gets wiped and when, and how they would spot contamination early. Everyone who cultures has lost a flask or a plate, so ask how the last one was traced.
What routine maintenance have you done on an instrument, and how did you know it was due?
Why ask it
Daily cleans, weekly checks and the service log are unglamorous, and results drift when they are skipped. A candidate who mentions the log before you do has worked somewhere that kept one. Find out what they would leave for the engineer.
Tell me about the last time an instrument stopped in the middle of a run. What did you check first, and when did you call for help?
Why ask it
The order is the answer: samples made safe, the error message written down, reagent levels, tubing and waste looked at, then the call. Both extremes cost you, the technician who phones service before looking and the one who opens panels nobody trained them to open.
How do you learn a method you have never run before?
Why ask it
Reading the procedure through, watching it once, doing it under someone's eye and then running known samples before real ones is the careful sequence. Notice whether they would ask why a step is there. That curiosity is what stops a person 'improving' a method without telling anyone.
Accuracy and records
Forty tubes arrive together for the same test. How do you make sure each result ends up against the right sample?
Why ask it
A swapped tube is the one error no control will catch, and only dull habits prevent it: labeling before filling, one rack order kept from start to finish, identifiers checked against the worklist at every transfer. If the answer is 'I am careful', ask what careful looks like at tube twenty-three.
What do you write down while you work, and when do you write it?
Why ask it
The second half is the test. Entries made as the work happens, with lot numbers, times and anything that departed from the procedure, can be relied on later. Notes rebuilt from memory at the end of the day cannot, however neat, so ask what yesterday's entry contained.
You notice that you wrote the wrong value in a record an hour ago. What do you do?
Why ask it
One line through the error so it can still be read, the right value, initials, the date and a reason is the paper habit many quality systems teach, with an audit trail doing the same job on screen. Your rules may differ, so judge the instinct: corrected in the open, never overwritten and never a page removed.
Which laboratory software have you used to log samples or record results, and what did you enter in it yourself?
Why ask it
Your system is probably a different one and can be taught, so the product name matters less than what they did inside it. Registering samples, entering results and amending an entry with a reason attached are three different levels of trust.
Tell me about a mistake you made at the bench. How did you find it, and who did you tell?
Why ask it
Anyone with real bench time has mislabeled, miscounted or thawed the wrong box. Score how soon they spoke up and whether anything changed afterward. Be wary when the mistake has become a colleague's by the end of the story.
The written procedure says one thing and everyone in the lab does another. What do you do?
Why ask it
This happens in most labs, so claiming never to have seen it is not the good answer. The good one takes it to the supervisor so that either the practice or the document changes. Quietly picking whichever version is quicker is the reply to worry about.
How do you keep track of reagents: lot numbers, expiry dates and what was opened when?
Why ask it
A date written on the bottle at opening and a look at the expiry before each use are the minimum. Go one step further and ask what they did on finding something out of date already in use. It is a small test of whether they report a problem or just swap the bottle.
Someone else has to finish your run tomorrow. What do you leave for them?
Why ask it
A handover is a record written for a reader, and it shows whether a person thinks past the end of their own shift. Look for where the samples are, which step was reached, what looked odd and what is still owed. A text message is fine as an extra and thin as a system.
Quality control
A result looks wrong to you. What do you check before you report it, repeat it or tell anyone?
Why ask it
A sound order runs from the cheapest check outward: the sample itself, its identification, the controls on that run, the reagent, the instrument, and only then a repeat. Ask for a real case and what first made them suspicious. People who know what normal looks like on their bench are the ones who catch things.
What controls did you run in your last job, how often, and what did you do with the numbers?
Why ask it
Running controls and reading them are separate skills. You hope to hear about ranges, a chart or log looked at across days, and a slow drift noticed before anything failed. If the answer stops at 'they passed', ask who decided what passing meant.
A control fails halfway through a busy run. What happens to the samples you have already measured?
Why ask it
The reply shows whether they see a control as vouching for a batch or for a single moment. Your quality system will have its own rule for this, so explain it afterward. What you are scoring is that they stop, hold the affected results and ask, and do not release the earlier ones because they 'looked fine'.
A ward, a production line or your PI is waiting on a number that you are not yet satisfied with. What do you tell them?
Why ask it
Pressure to release is part of most labs, and people who have worked a busy bench can describe the last time they felt it. Listen for a time being offered ('twenty minutes, once the rerun is off') in place of either the doubtful number or silence, and for the supervisor hearing about it. Who may hold or release a result is set by your own procedures, so explain that once they have answered.
Your repeat gives a different answer from the first run. Which one do you report?
Why ask it
'Neither yet' is the answer worth hearing. Two numbers that disagree are a problem to look into, and choosing the one that seems more plausible is how bias gets into data. Ask who they would bring in and what would go in the record.
A sample arrives that you think should not be tested: the wrong tube, leaking, unlabeled or too old. What do you do?
Why ask it
Every lab sets its own rejection criteria, so describe yours once they have answered. In a clinical lab a rejection can mean a second needle for a patient, and in research it can mean a time point that cannot be collected again. You want someone who neither tests whatever is handed over nor throws it out without a word to the sender.
Have you calibrated an instrument, or done the routine check on a balance or a pH meter? Talk me through the last time.
Why ask it
Choose the item your lab leans on. Detail is the evidence: which standards or weights, what tolerance they were working to, where the outcome was recorded and what happened to a unit that failed. A candidate who has only ever watched it done will usually say so if you ask kindly.
Have you been through an audit, an inspection or a proficiency test? What was your part in it?
Why ask it
Which bodies inspect a lab depends on its type and location, so the names they mention may not be yours. Attitude is the useful part: an inspection as a reason to tidy what should already be tidy, or as theater put on for the week. In a research lab with no outside inspector, ask about a time their data had to be traced back to the notebook.
Safety and samples
What protective equipment did you wear for your routine work, and when did you add to it?
Why ask it
Lab coat, gloves and eye protection should come out without thought. When they added to it is where judgment shows: a face shield where something could splash, a fume hood for a volatile, different gloves for a solvent. The same gear for every task means nobody was assessing the task.
Tell me about a spill or a broken tube you dealt with. What did you do in the first minute?
Why ask it
In a good account, warning the people nearby comes before any cleaning, then the right spill kit for what it was, then a report. Ask whether it was written up. A lab where small spills never get recorded learns nothing from them, and a candidate can carry that habit to you.
How do you handle samples that could be infectious?
Why ask it
For clinical, veterinary and microbiology benches. Treating every specimen as a possible source of infection, working behind a barrier where aerosols can form and washing hands on the way out are the basics. The rules that bind your lab come from your own safety office, so go through those on the first day whatever is said here.
Part of this job is work some people would rather not do, such as taking blood from patients, handling animals or working with human tissue. Have you done it, and how do you feel about it?
Why ask it
Name the task your lab really has, and skip this if there is none. People are entitled to a limit here, and it is far better heard at interview than in week three beside a mouse cage or a nervous patient. Ask what they were trained and signed off to do as well. Who may do this work in your lab depends on your own rules and approvals, so check those before you count on anyone's past experience.
Which hazardous chemicals have you worked with, and where did you look when you had to handle one for the first time?
Why ask it
The safety data sheet, the label and the lab's own risk assessment are the three sources a trained person names. Storage makes a good follow-up: what they kept apart from what, and where the flammables lived. 'I asked someone' is fine when the someone was the right person.
How do you sort laboratory waste at the end of a run?
Why ask it
Sharps, biological, chemical and ordinary waste each go their own way, and the categories and container colors change from site to site. You are checking that they expect a system and would ask about yours. The technician who assumes the old containers apply is the one who pours solvent down a sink.
A sample has to stay cold, stay frozen or reach the instrument within a set time. How do you keep track of that across a busy morning?
Why ask it
Good answers have a mechanism in them: a timer, the receipt time written on the worklist, a cold block on the bench, batches small enough to finish. Then ask about storage, and what they did the day a freezer was alarming or its door had been left ajar.
What do you do with patient or participant details that come with a sample?
Why ask it
Only for clinical labs and research with human samples. Privacy rules differ by country and institution, so this is not a test of yours. A sound instinct is to use only what the test needs, discuss nothing outside the lab and lock the screen, and then to ask how it is done here.
Workload and team
Sixty routine samples are waiting, an urgent one arrives and an instrument alarm is sounding. What order do you take them in?
Why ask it
Build the scenario from your own lab, so the right order is one you know. Listen for a reason behind the order and for who gets told about the delay. A candidate who asks you a question before answering, such as what the alarm is for, is showing the habit you want.
How do you stay accurate through hours of repetitive work?
Why ask it
Much of a technician's week is the same procedure again, and the candidates who last are honest about that. Practical answers are the good ones: sensible batch sizes, a short break before the step where errors happen, a check of the first and last tube in each rack. If repetition plainly bores them, a routine testing bench will not keep them long.
Here is the schedule this bench runs, including any nights, weekends or out-of-hours time points. Which parts of it can you commit to?
Why ask it
Describe the true pattern first, including how often cultures, animals or a time course pull someone in outside normal hours. Keep to availability and leave the reasons alone, since family and health are not interview topics. Your HR contact can tell you exactly where that line sits for your employer.
Have you worked alone in a lab, at night or over a weekend? What was different about it?
Why ask it
Working alone changes the job: nobody to show a doubtful result to, and nobody close by if something spills. People with shift experience mention knowing who to phone and which tasks they would leave for the morning. If your lab has a rule about lone working, explain it now.
Several people give you work at once, and each of them wants it first. How do you decide?
Why ask it
For a technician who supports a whole group this is a weekly event. The answer to hope for sends the clash up to whoever sets priorities, instead of settling it by who asked loudest. Tell them who that person is in your lab, and if you cannot, settle it before you hire.
Someone you share a bench with keeps leaving it untidy, or finishes a reagent and does not reorder it. What do you do?
Why ask it
It sounds small, and it is the kind of thing that sours a shared lab. The useful answer starts with a word to the person, goes to the supervisor only if it carries on, and involves no notes taped to the freezer door. Where an empty bottle could stop somebody's run, check that they would also deal with the bottle that day.
How do you like to be supervised: checked often, or shown once and left alone?
Why ask it
Neither preference is wrong, and either has to match you. Say how you really supervise, how often you are in the lab and who answers questions when you are away. A technician who wants daily contact and a PI who travels half the month are a mismatch you can see from the interview room.
Your supervisor asks you to do something you believe would compromise a result or skip a required step. What do you say?
Why ask it
Leave a pause after asking, because it is awkward to answer in front of the person who would be that supervisor. You hope for a respectful check first ('can I make sure I understood?') and then a plain refusal to record something that did not happen. Thank them for a firm answer so they know it was the one you wanted.
A good share of this job is restocking, washing glassware, ordering and keeping the freezers in order. How much of that have you done, and how do you feel about it?
Why ask it
Give the real proportion, even if it is a third of the week. People who have run stock well talk about noticing what is low before it runs out and keeping a list other people can read. Polite silence followed by a question about when they could move on to experiments is an answer as well.
Where does a technician job sit in your plans: a year or two before further study, or the work you want to keep doing?
Why ask it
Some people take a technician post on the way to graduate school, medical school or a specialist qualification, and for others it is the career. Either can suit you, as long as you know which you are hiring. If they expect to leave for a degree in a year, decide whether one good year repays the training.
What would you like to ask us about the lab, the bench or the team?
Why ask it
Leave real time for this and, if you can, follow it with a walk through the lab. What they ask shows what they care about: the instruments, who would train them, how busy the nights get. Answer straight, including the parts of the job nobody loves.
How to interview a lab technician candidate
Practical guidance for the conversation itself
Before the candidate arrives
Write the bench down first
List the six or eight tasks this person will do in an ordinary week, with the instruments by name, and choose questions against that list. A hospital chemistry bench, a university research group and a factory quality lab each need a different half of this page. A question about sterile culture is wasted on someone who will spend the week at a titrator.
Three to keep whatever else you cut
An hour has room for perhaps a dozen of these once follow-ups are counted, so most of the page goes unused in any one interview. Whatever you cut, keep the dilution on paper, the result that looks wrong and the mistake at the bench: between them they show arithmetic, judgment and honesty, which no question about motivation reaches. Put the same set to every candidate, so that afterward you are comparing answers to the same thing.
Check your own rules before you ask about theirs
Required qualifications, who may release a result, what has to be recorded and how long records are kept all vary with the type of lab, the country and the employer. Ask your quality lead, safety office or HR what applies to you before the interview. Treat what a candidate describes as how their last lab worked, not as the standard.
Bring someone who works the bench
A senior technician hears what a manager misses: a step out of order, an instrument described from the brochure, a timing that could not be right. That person will also stand next to the new hire every day, so their view of the fit counts for a lot.
Make part of it practical
Paper, a pipette and a label
The dilution question and the pipetting question are quicker to watch than to discuss. Ten minutes with water, a tube rack and a marker shows care, order and whether the person says units aloud as they go. Use nothing hazardous and no real samples, and give every candidate the same exercise.
Show them one of your worksheets
Hand over a blank run sheet or notebook template and ask what they would fill in and at which point in the work. People who keep good records start asking where the lot number goes and who signs the review box. If you show a completed page, remove anything that identifies a patient, a participant or a customer first.
Finish with a walk through the lab
Ten minutes among the benches lets the candidate see the instruments and lets you see what they notice. One will ask about the maintenance log on the analyzer, another will look for the eyewash station. Check your site's visitor rules beforehand: footwear, a coat, and the rooms a visitor may not enter.
A trial shift is a bigger step than it sounds
Asking a candidate to work part of a shift raises questions about pay, insurance and access to samples or confidential data, and the answers depend on where you are and who employs you. Speak to HR before you offer one. A supervised demonstration with water and dummy tubes tells you most of what a trial shift would.
What to do with a vague answer
'We' in every sentence
Ask which steps were theirs. In a shared workflow one person prepares, another loads and a third reviews, and all three resumes say 'performed'. Whoever did the whole thing can also tell you what it looked like on the day it went wrong.
A brand name and nothing after it
Naming an analyzer is not the same as running one. Follow with the daily start-up, how long a run took, or the last error message it gave. Real users answer at once and often with a small groan.
'I would just repeat it'
A repeat is sometimes right, but as a reflex it hides the cause and uses up sample that may be scarce. Ask what they would look at before repeating, and what they would do if the second number did not match the first.
A spotless record
A technician with years at the bench and no error to describe has either not been checked or is giving the answer they think is safe. Say plainly that you expect mistakes and are hiring for how they are reported. Many candidates then produce a perfectly good story.
'I work fast'
Speed is welcome once accuracy is settled. Ask how many samples an ordinary day held, how the count was reconciled at the end of it, and what they slowed down for.
Adjusting the list to your kind of lab
Clinical and diagnostic labs
Weight the list toward sample identification, rejection, controls, urgent work and shifts. Credential and registration requirements for people who test patient samples are set locally, so confirm yours before you advertise and ask the candidate to bring the documents. Add one question about phoning a result that cannot wait, built on your own procedure.
Research labs
Weight it toward technique, notebooks, long experiments and serving several people at once. Where a question says 'controls', the candidate may think of the positive and negative controls inside an experiment, which is the right reading for you. Be open about how long the funding for the post runs, because a good technician will ask.
Industrial and quality control labs
Here the weight falls on following a written method exactly, calibration, documentation and what happens when a result is out of specification. Ask the audit question early. Someone from a regulated lab will already speak that language, while someone from a university may be an excellent analyst who needs the paperwork culture explained.
A candidate with no lab job yet
New graduates have teaching labs and perhaps a project or an internship. Change 'your last job' to 'your lab course', and lean on the paper calculation, the pipetting exercise and the questions about recording and owning up to errors. Habits show in a teaching lab just as they do in a job.