A chimpanzee is not a pet easily found on a pet shop. You can’t go down the street, go buy some dog food and gram a chimp for your scientific experiments. It could work with mice, probably (the ones that are used to feed snakes, for instance). But what about our cousins? I am pretty sure you also can’t go in the jungle and catch a chimp.
Is there some sort of shop for such a thing? The market for that can’t be that large - after you get some specimens they will take care of the miracle of multiplication…
You have more or less answered your own question. There are facilities for breeding various sort of primates (and other, more commonly used animals, such as white rats, and mice) specifically for research purposes.
Scientists that do animal research generally don’t get their specimens from the wild or from a pet shop (unless they are specifically interested in studying animals from those types of populations). There are dedicated breeders for all kinds of research animals including rats, mice, monkeys, apes and even fruit flies. The breeders for those types of animals have to maintain strict records about the lines that they are supplying and may have genetic variations on them available even within the same species. Research mammals are generally very expensive compared to animals from less controlled sources even in the case of animals that are common elsewhere like rats and mice because they come from known stock and and good health which is very important in research.
Some larger primate research centers run their own breeding programs as well. Here is an example of one research primate breeding facility in the U.S. but there are many more.
