The problem is that short reads don’t necessarily let us know how the big picture should be assembled (what researchers call building the DNA scaffold). This is especially true in the case of DNA that’s very repetitive—think of it as a puzzle with lots of pieces in the same color. The order still matters, but without the clues you get from color variation it can be hard to know which piece of sky goes where. And durian, as it turns out, has a lot of the same puzzle pieces: according to the new study it has 46,000 genes—roughly twice the number found in human DNA—that are mostly just repeats of a smaller original set. So the researchers turned to long reads sequencing, which allows researchers to see bigger pieces of the DNA scaffold to guide the order of their short bits. Finally, they used a third technique known as Hi-C to show them how to properly line up all the scaffolds they assembled.