There are a few different mixing situations you might encounter:
- Mixing the same material type from different upstream steps
- Mixing multiple batches of one material made in a single upstream step with the same properties. (For example, mixing multiple batches of cell culture of the same strain intended to be inoculated into one downstream fermenter.)
- Mixing multiple batches of one material made in a single upstream step with different properties. (For example, mixing a combination of three different catalysts in each run in one experiment.)
Case 1: Mixing the same material type from different upstream steps.
Suppose you were mixing batches of hot and cold water prepared in an upstream step. You could use either of these patterns in your design:
The second configuration is generally what you want because you can explicitly specify how much of each upstream material you need in the downstream run. The first configuration does not presently allow such specification in your experiments. (To get configuration 2, you need to drag the input resource from step 7 to step 5 or 6, not the other way around.)
Case 2: Mixing multiple batches of one material with the same properties
Suppose you were mixing multiple batches of pre-heated water, each prepared in the same way, into a downstream reactor. You have to do this because your heating containers are too small to heat up all the volume in one batch. But you also may need a different amount of water (and therefore a different number of batches) in each experiment. You would design your process like this.
Here you can add as many batches of water as you need in the Make water step, then merge them all into the same input resource downstream in the Mix water step (The blue highlighting means the upstream batches are merging into the yellow downstream selected batch.) But all the batches have to have the same input property of 20mL volume on the input. Due to a current limitation, this merging cannot be done via a file upload and only the name of the last batch merged is shown downstream (GR-7gJC).
Case 3: Mixing multiple batches of one material with different properties
Now suppose you are mixing multiple batches of water with different properties, where each batch is made in a single upstream step. For example, mixing a hot and cold water. You may need different amounts of each of these batches. (In a typical experiment you might be mixing enzymes, or catalysts, or substrates, not water as is illustrated here.)
You can address this by adding an input resource (e.g. “water”) to the mixing step twice. This works, but it can get confusing later which input is which when you need to select them in drop down menus or in the data table you use for analysis. Instead, to distinguish these repeated resources, it is helpful to create new resource types such as “water 1”, “water 2” and “water 3”, or in the case below “hot water” and “cold water”.
You can then assign your water that you made in the Make water step previously to these two inputs (even if the hot water and cold water have a different resource type). In this case, hot and cold water are both of the water, tap resource type because they were both made in the upstream step Make water as shown below.
Note that these two steps are not connected in the flow diagram because you cannot connect steps with differing resource types on the outputs (e.g. water, tap) and inputs (e.g., hot water and cold water). And because the connections would not be able to prescribe which of the runs on step 1 flow to which inputs on step 2. Thus you need to keep them unconnected and manually assign the inputs on step 2.