Unlike some other service providers, Cofactor understands that many small labs have neither the need nor the budget for 100 million reads so we sell down to the individual sequencing unit for any number of libraries.
A given flowcell or slide can be mixed and matched with libraries types of the same ended-ness (single or paired/mate) from many projects and organisms.
However, if you purchase less than a full flowcell or slide, your samples must be run concurrently with samples from other customers to fill the batch so your wait time will be both longer and more variable. As mentioned above, you can pool your own separate experiments or experiments with your collaborators on a single flowcell or slide if you like.
You can do your part to minimize the total wait-time by submitting your samples as soon as you choose Cofactor, making your 1/2 upfront payment as quickly as possible, and ensuring that you have submitted sufficient, high-quality samples by assaying their quality before mailing.