A quasi-replicate is a factor whose levels are not included in the design calculation, but rather define how many times the entire design is replicated for each of its factor levels.
For example, if in your experiment you have cells from three different donors, and you want to calculate the variability across the different donor sources of cells, you may wish to replicate your entire design three times, based on the factor ‘Donor Cells’.
In Synthace, any factor specified that is mapped to an element parameter or a Custom Factor can be a quasi-replicate factor.
In this tutorial you will learn:
How to set a factor as a quasi-replicate.
Defining a Quasi-replicate factor
Build a workflow that defines a set of liquids and provides those liquids to a Make Mixtures element.
Switch the workflow builder into DOE Mode.
Note: only the elements that can have DOE factors applied to their parameters will be interactive and display in colour. If the workflow has not already been added to a Synthace experiment you will be prompted to do so before being able to enter DOE mode.
Select the Make Mixtures element and toggle on the Mixture Compositions parameter to identify that you intend to describe these mixtures with DOE factors.
Note: factors within Diluent To Use **and Final Target Volume can also be specified as quasi-replicates in both Make Mixtures and Mix Onto elements.
Click the adjacent factor button in the Instance Panel to launch the DOE Factor Panel.
Add two new factors to the Make Mixtures 1 > Compositions parameter for Liquid A and Liquid B, with levels that sample a range between 10 and 100 mM. For more details on how to do this, click here.
Add a new categorical factor to the Custom Factors section called Donor Cells with levels Donor 1, 2 and 3. For more detail on how to do this, click here.
Click on the Quasi-Replicate check box before adding the factor to the factor table.
Note: In any factor that you set up in Synthace you have the option to treat it as a quasi-replicate factor by checking this box.
Check the Quasi-replicates
Click on the Calculate Design tab at the top of the Factor Table.
Note: Quasi-replicate factors are not included in the power calculations. They do not contribute to the actual design, but replicate the design the same number of times as the levels in your quasi-replicate factors.
Scroll to the Final Run Matrix at the bottom of the panel.
Note: While the calculated design only has 96 run, you will notice that you require 288 runs in total, 96 runs for each of the three Donor Cell types defined. Scrolling through the design matrix table, you will see that the 96 runs are replicated 3 times, once for each Donor Cells type. By default, the 96 run order is replicated exactly for each quasi-replicate, however you can choose various randomisation options at the top of the page in the settings panel.
Well done on making it to the end of this tutorial.
To learn more about quasi-replicate factors see here.
To learn about defining more than one quasi-replicate factor per design, click here.
To learn about the different quasi-replicate randomisation options, click here.