How to do better DNA experiments
Friday 6 February 2015
In the new IB guide there are many references to methods in biotechnology which appear to be impossible to do practically in the lab. DNA profiling, gel electrophoresis, genetic modification of plasmids, genetic screening or using DNA to build cladograms showing plant evolution are notable examples. All to often students are pointed towards online simulations during these topics but this need not be so.
NCBE in Reading university have a number of biotechnology kits which could be used during the genetics topic and also in the biochemicals topics. These kits could be used in individual investigations too.
The simplest is a DNA extraction kit with a nice glass pendant necklace so students can actually wear their DNA afterwards. This extraction is a bit basic and there are more exciting kits.
The best way to illustrate DNA profiling using PCR and then electrophoresis comes in a kit to extract DNA from chloroplasts in leaf tissue. There is a surprising amount of DNA in the chloroplast. The PCR part of the experiment can be done using water baths if you don't have a PCR machine and there are loads of details and practical help on the NCBE 'The PCR and plant evolution' webpage.
For all the kits the materials are well thought out and the equipment has been carefully designed to work in a school laboratory and at an affordable price. There are a range of kits to choose from and during the next few months NCBE will be releasing some really exciting synthetic biology kits where gene precursors can be used to switch on or off fluorescent protein genes in transformed bacteria. This might be really useful in the sections of the new guide which refer to gene expression, and in topic 3.5 of Genetics. The catalogue is well worth a look and can be found on this NCBE welcome webpage.
Some of the kits may not be available for delivery worldwide but it is always worth contacting NCBE for advice.