The Bradford Assay is a simple protocol to measure protein concentration. It uses a dye called Coomassie Brilliant Blue, which binds to proteins and becomes unprotonated, leading to a change in its absorbance spectrum. As such the Beer-Lambert law can be applied and a relationship between absorbance and protein concentration established.
Get started
Read the introduction to this series of tutorials, then complete all of the previous tutorials in the series. For more information, click here.
Create a copy of the workflow that you created in Core elements tutorial 10.2. To learn how, click here.
Rename the copy Core elements tutorial 10.3. To learn how, click here.
Add a Bradford Reagent
To convert the above workflow to a Bradford protocol, Bradford reagent needs to be added onto our aliquoted samples and standards. We will use the Mix Onto element. For more information on how to use this element, click here.
Add a Define Liquids and Plates and a Mix Onto element to the builder.
Define a liquid called Bradford Reagent at a 2x concentration.
We want to add the reagent onto the plate with the samples and standards, so connect the Aliquots output of the Aliquot element to the Destination Liquids input of the Mix Onto element.
Additionally, connect the Liquids output of the Define Liquids and Plates element to the Source Liquids input of the Mix Onto element.
Click on the Mix Onto element to open the element parameter editor. In this case, we want each sample and standard to receive the reagent, so we specify the addition mode to Mix In Order.
The new mixtures can inherit the names of the liquids already on the plates, in this case the samples, or you can specify a new name. In this case, we will not rename the mixtures so select the option Do Not Rename.
Now, we can define the volume of each reagent that should be added to the cell lines. In this case, the reagent should be added with the same volume, so specify a default value.
Importantly, you can specify a number of times, or replicates, you want the reagent to be added to the plate. For this protocol, this number is the number of liquids already on the plate. Considering that this is a workflow which could potentially be run with different numbers of samples, it is desirable to have the number of replicates scale automatically. To do so, instead of specifying a number, connect Output Liquid Count from the Aliquot element to Replicates on the Mix Onto element. This way, the number of replicates will be the same as the number of samples, and automatically scale as the number of samples changes.
Simulate the workflow
Check that the device that you selected can follow the instructions that you prepared. To learn how, click here.
Preview the execution
After you simulate the workflow, click View Simulation to open the simulation details.
Open the Preview tab, then click through the steps to check that the instructions that Synthace has generated are correct.