Saturday 8 September 2018

Experimental Planning 1.Work Flow Diagrams

1.Work Flow Diagrams as an aid to planning


This series of posts is intended to introduce newcomers to the key elements of experimental science. In this first post, I shall discuss the elements of planning and preparation. I believe the success of any experiment is directly related to the care taken in preparation and planning.
If you set out to bake a loaf of bread, go on a holiday, get ready to run a marathon or revise for an examination, there is always an element of planning and organisation involved. The better prepared you are the more likely the outcome will be under your control. So if you are travelling to the USA for the first time, you will need to organise tickets, a passport, a visa, dollars or some form of credit card, accommodation, onward travel and possibly arrange tickets for the opera etc. If you want to travel to the USA at short notice, then there are a number of consequences. Without a passport, you will be unable to travel at all, unless you organise a 1 day passport, but for normal passport applications, this may take between 2-8 weeks. You will need a visa, but if you have internet access and online credit you can organise this the day before. As you can see, some things require planning and organisation. 

I want to introduce you to the concept of the  Work Flow Diagram which is a popular way for experimental scientists to organise an experiment and in addition, provide you with a framework for noting down any observations as you go through the day's protocols. I want to avoid a rush to get started, which can lead to wasted time and effort: something that must be avoided. Starting any experiment without any serious planning is a recipe for disaster! Constructing a Work Flow Diagram should form the first activity in the morning. You will begin to get familiar with my approach of never running lab work like a structured class practical, in which all reagents and solutions are provided, rather you have to plan your experiment and obtain the materials. To help you with this we shall make use of the Work Flow Diagram (WFD for short) in every lab session and it must be approved before you get started.

What should a good WFD look like? The diagram should include a brief title, the overall aim of the experiment(s), the sequence of steps which should include any key pre-incubations (e.g. pre-heating agar plates, thawing frozen samples, preparing fresh reagents, ensuring you have tubes ready for aliquoting samples etc.) You might construct a Table to help you organise the composition of multi-component assay mixtures (where appropriate), and you might work out the dilutions of samples in order to ensure the data that emerge cover the appropriate numerical range. 

I am keen for you to develop a style of your own, but as you will appreciate, a typical WFD will have some common features and some specific features that relate to the experiment and the materials. There should also be space on the WFD for noting observations, which may include suggestions for improvements, or steps that can be eliminated etc. It should be a live document! I will be asking you to produce a WFD in all classes, so start thinking about the way you will approach this. For your first induction project, you will be given help in constructing your first WFD in the first session of the Biology and Chemistry mini-project. I look forward to discussing the outcome with you when we get together  during the following week.

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