Monday, 27 January 2014

The importance of planning experiments

Experimental Science. The journey from a student to becoming a practicing scientist never ends, or at least in my view it shouldn't. One of the things that I find most frustrating is a day spent with students carrying out an experiment while racing against the clock. Under these circumstances there is little chance of acquiring new skills (or even honing old ones) and an appreciation of the over-arching concepts, the significance of each step and ultimately an understanding of the outcome, are all lost in the process. In short the exercise is largely pointless. So, how should you approach your time in the lab? Below are some suggestions.

Listen, make notes, read instructions carefully and discuss your understanding with your group members. I generally find that taking notes during any meeting helps me remember things (and some say it aids in understanding). I recommend that you have a small notebook and pen with you when someone is giving a presentation in the lab or in a seminar (or in any meeting). If you have been given instructions or you are searching for information on the internet, read the instructions carefully. Avoid jumping into an experiment until you have mentally "walked through" all of the steps. 

Team-work. As a group you should then make sure you all understand what you have to do. Then allocate tasks and begin to get organised. Gather materials, clarify any uncertainties (after you have attempted to understand) with a demonstrator and write out a schedule for the day: we call these a work flow. This can form the basis of your methodology write up later.

Observation. I cant stress how important it is to keep watching what is happening to your samples, the amount of a solution that you dispense, the colour or appearance of a fraction from a column or a tube in an incubator. Again, make notes of what you observe. Some of these observations may not be important, but treat everything as important as you go through the experiment. It is only later that you can decide which observations should be included in the analysis of your results. 

Sample labeling. So far everyone has had an experience of losing their samples from one week to the next. Since we are running lab projects over several weeks, tracking your samples is vital. Think about how you label samples and don't leave it until the last minute. A petri dish labelled on the lid, is an experiment wasted if the lid is accidentally knocked off by you or a colleague in a shared fridge or incubator. Tubes labelled 1,2,3 or A,B,C will become forgotten among the multitude of As and Bs and Cs. If the sample is to be frozen, think about the likelihood of the label being lost. Use the right kind of pen/ink or sticker. Also write down the labels you have used and the location of your sample.

Tidy your bench. Before you leave, allow time to tidy your bench. This is considerate and polite, since someone else will have to do it for you: and that's unfair and unsustainable. Secondly, by tidying, you make sure that your solutions, samples and equipment are kept in the right place and temperature and that the equipment is well maintained. This is not an option.

Writing up your experiments. You have all been given clear guidelines for writing up your experiments. Take your time, think about the significance of what you have done and what you have observed. Experiments do not "work" or "fail", they give you outcomes or results that are influenced by many parameters: the reagent quality, the skill of your manipulations, proper use of instruments from pipettes to spectrophotometers etc. Therefore write up what happened and explain why you think you obtained your particular set of data. As you gain experience, your skills will improve and your ability to obtain robust data will also improve. This is a learning process and it never stops!

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