Lab skills quiz – working in the lab


Which of the pipettes above is set to dispense 32.7 μl?
Nope, that is 327μl (far too much for this pipette
  Nope, that is 327μl
Nope that is 3.27 μl
Why should you be extra careful when using Ethidium bromide?
It melts plastic
clue: think about techniques that use EtBr… what’s the purpose of adding EtBr?
It denatures proteins
clue: not directly, but could indirectly impact proteins….!
It intercalates into DNA, and therefore may cause DNA damage
Ethidium bromide, midori green, SYBR safe, and other DNA binding dyes are often used when running agarose gels. Most of these dyes bind directly to the DNA and are thought to be mutagenic. Make sure you protect yourself when working with these (and other) chemicals!
It is a potent neurotoxin
You are about to thaw a vial of cells, what hazards are associated with retrieving the cells from liquid nitrogen (select all answers that apply)
Asphyxiation hazard from liquid nitrogen
Yes! Nitrogen is heavier than oxygen therefore the oxygen in the room will be forced upward. If you have a spill or leak there will be a risk of asphyxiation. You should never travel in a lift of work in an enclosed space with liquid nitrogen. In our research institute you must wear and oxygen monitor when working with liquid nitrogen.
Burn hazard from liquid nitrogen
Yes! Extreme cold can cause burns just as easily extreme heat. Wear protective clothing; mask and gloves, to protect against splashes. No open toed to shoes to protect against spills etc.
Fire hazard from liquid nitrogen and open flame
clue; actually you have the opposite problems…
Electrical hazard from liquid nitrogen and electrical sockets
this isn’t a major concern as liquid nitrogen will immediately sublimate at room temperature. Pick again.
 When you leave the lab, what happens to your lab book?
It remains with the lab/supervisor
Yes! the lab book is a record of what you did for other people to see. People who follow you will need the details of your experiment if they are to repeat your work. The evidence in your lab book might be required for future publications or to prove first discovery with respect to intellectual property. Make sure it is up to date, contains complete details and is legible!
You take it with you as a resource for your future experiments
Nope. If you think you will need it in the future then you should copy what you need before you leave
It is incinerated
of course not! lab books contain important evidence, they need to be safely stored for extended periods of time
It is deposited in the central library of the institution in which you work
some institutions may have a long-term store for archived material, but most likely the lab book will needed to be accessible in the short-term and so is unlikely to be archived straight away.
What constitutes authorship of a paper? (according the to the international journal of medical editors’ guidelines) A: providing funding,
B: providing samples,
C: contribution to the design of the work,
D: providing lab space,
E: head of department,
F: acquisition, analysis or interpretation of the data,
G: drafting the manuscript or revising it critically for intellectual content.
H: final approval of the version to be published and agreement to be accountable for all aspects of the work. choose all that apply
Of course you could do more than this too, but this is the official minimum. it isn’t enough to just do the data collection, you actually need to be involved in the writing process, and ultimately by agreeing to be an author you are agreeing to be responsible for the work.
While money, power and space matter, if they aren’t part of the key basis of the story then they aren’t sufficient to count as an author; these sorts of contribution are acknowledgements. Securing, in the form of writing a specific grant application, will usually involve planning experiments, and, as such, would fall into category C in addition to A
Just being involved in the writing stage isn’t usually enough unless there are some contributions to the data interpretation. Editing word choice, grammar, spelling or making aesthetic comments on figure presentation are things you should do as a good colleague.
Unless you have contributed to the design of the patient recruitment strategy or acquisition of the samples in some meaningful way, then it is likely more appropriate that provision of clinical samples is and acknowledgement rather than authorship. Note if you provide a reagent that requires extensive design/validation AND contribute intellectually to the manuscript it likely would be appropriate for inclusion in the author list.
Not enough, you have to contribute intellectually to constructing the paper. Realistically, making the data figures is likely sufficient but different lab heads might have different ideas.
Under which situations would a journal demand that a published paper be retracted? select the 4 correct answers
The findings have previously been published elsewhere without proper cross referencing, permission or justification
dual publication of research data is not permitted.
There is clear evidence that the findings are unreliable as a result of misconduct
Fabricating or manipulation of data is an example of misconduct which would make the findings unreliable. Manipulation includes adding or taking away individual data points, being selective about data presentation or not presenting data that doesn’t support your hypothesis (cherry picking)
The paper reports unethical research
There is evidence that the findings of the paper is unreliable due to honest error e.g. miscalculation or experimental error
Even if it is a mistake, if a error influences the interpretation of the data the paper should be retracted. If you discover such an error you should start the retraction proceedings.
The author / contributor list is incorrect (i.e. a deserving author has been omitted or somebody who does not meet authorship criteria has been included)
In this case, the journal would issue a correction rather than a retraction, assuming there are no issues with the interpretation.
A subsequent publication makes opposing findings.
There may be many reasons why results are different between studies. As long as the data are true and honest then there are no reasons to issue a retraction
There is evidence that the findings are unreliable but the authors’ institution will not investigate the case
In these situations the journal will publish an “Expression of Concern.” Although this doesn’t sound as bad as a retraction it will still seriously harm your credibility and therefore career until the situation is resolved.
What specific additional precautions should you take when using a substance with this label on it?  
Keep it away from flammable material
this symbol means oxidising, it does not burn itself but rather provides an oxygen source for flammable materials
Do not use plastic containers
Use in a well ventilated area
Do not use while wearing a wig or hat
Do not turn the bottle upside down
What does this symbol mean.
Yes, it is used for less serious health hazards like skin irritation
Dangerous to the environment
Gas under pressure
Warning, excessive punctuation
You have bought a new reagent, on the data sheet it says  “stable at 4C for 1 month, for long-term storage up to 1 year, store at -20C” and “avoid repeated freeze thaw”. You don’t think you will use the whole vial in the next month, what should you do?
Tell the technical team or lab mates to arrange aliquoting and storage
Your lab might have technical support that provides this service, however, you should be the one responsible for your reagents. By all means ask the tech team for advice on what to do but don’t assume that they will do your work for you!
Calculate how much you will use in each experiment and aliquot the reagent into those amounts into labelled tubes and store in a labelled container in a lab freezer
Aliquot into 20 tubes of equal volumes, label the tubes and store in a lab freezer.
Store at 4C for the first month and then aliquot whatever is left
Storage of reagents is to maintain their function, if you adopt this approach then you will i) risk forgetting ii) will have some experiments where the reagent has been used directly and others where it has been freeze/thawed introducing an unintended variable iii) as the reagent goes “off” even at -20 then you will be unlikely to get the full year worth activity.
What temperature should your test solution be for the pH measurement to be accurate?
The same temperature as the buffers used to calibrate the meter
Yes, the pH electrodes respond differently depending on the temperature, therefore make sure you heat/cool the calibration buffers to the temp of your test solution before measuring.
22.47 °C
Wow, that’s very specific…
Not necessarily, it is possible to pH hot/cold solutions too, try again
Not necessarily, it is possible to pH hot/cold solutions too, try again
As close to 0°C as possible without the solution freezing
No, think about what you do first when using a pH meter


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