When you come to load an agarose gel with your DNA/PCR samples, you will first need to mix them with a loading buffer. The loading buffer is a coloured solution that makes your sample visible during the loading process and helps to keep it at the bottom of the well. However, mixing your samples with a loading buffer is often performed in a separate PCR tube and can turn into a very laborious process if you have loads of samples. Think about all of those tubes you will have to get out and label, then one-by-one add the samples to the new tubes, then to mix each one with loading buffer before even getting to the point where you can load them onto a gel. Well, this is where Parafilm can speed things up!
Using Parafilm to mix your samples
Parafilm is a nifty plastic tape that is often used throughout the lab for sealing and covering containers. But using Parafilm to mix your DNA/PCR samples with the loading buffer takes advantage of its versatile properties, saves using additional PCR tubes and is super quick.
Here is how to do it:
1. Cut off some Parafilm, discard the paper backing and place the Parafilm on the bench with the shiny side facing up.
2. Pipette the required volume of loading buffer directly only the shiny Parafilm surface. For example, add 2 μL of 5x loading buffer if you want to load a final sample volume of 10 μL onto the gel.
3. Pipette 10 μL of your sample and mix it with the 2 μL loading buffer directly onto the Parafilm by pipetting up and down at least 5 times.
4. Load the sample onto the agarose gel as you normally would.
There you have it. A quick and simple tip on loading an agarose gel in no time.