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Use supplies nobody else is using
Curative, a health insurer that began as a Covid testing company, called its approach an orthogonal supply chain. Existing suppliers might stretch from making 1x of a consumable to 1.2x. If every lab is trying to buy it, one more buyer doesn't raise the number of tests being done and just adds to the squabbling.
The starting question was what it would take to scale to hundreds of thousands of tests a day. The method only fits a pandemic, since outside one nobody wants ten times more testing than they wanted yesterday.
Swabs came from vendors that supplied other uses, including electronic testing, and were then sterilized. For extracting genetic material, the default is magnetic beads, which come from basically two factories in China. Filter plates do the same job and are basically just glass and plastic, which can be scaled faster. So Curative found vendors able to scale glass and plastic manufacturing and partnered with them to 10x it.
How do magnetic beads extract genetic material?
Magnetic bead kits use tiny particles coated with silica or a similar surface that binds nucleic acids in a salty solution. A magnet pulls the beads to the side of the tube, letting the liquid and impurities be washed away. A final solution frees the purified RNA from the beads. The method is easy to automate, which is why labs came to rely on it.
How do filter plates do the same job?
Filter plates use a silica membrane in each well. When a lysed sample is pushed or pulled through with a binding salt, the nucleic acids stick to the membrane while other material passes through. Washes remove impurities, and a low-salt liquid then releases the clean RNA. The plates are made of glass fiber and plastic, so their production does not depend on specialty magnetic materials.
Why did swabs run short in early 2020?
Flocked nasopharyngeal swabs were made by a small number of manufacturers before the pandemic, with major production in Lombardy, Italy, and in Maine. Demand jumped within weeks as testing grew. Making a medical swab involves precise fiber application and sterilization, which cannot be scaled overnight. That concentration drove labs to look for other suppliers.
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