They came up with a promising candidate, tweaked it so it would be absorbed in the blood as a pill and then performed the key experiment testing it in mice to see if it would shrink tumors.

WSJ: New Medical Strides Against Prostate Cancer

The reason it typically takes two days to conduct a blood test and it can take as long as five is that once a nurse takes a blood sample, it must be sent to a central lab where the blood is cultured or amplified in order to let any infections grow and then cleaned.

FORBES: MIT Spinoff, T2 Biosystems, Hopes To Slash Deadly Hospital Infection Deaths

Existing models are based on indirect measures of how infectious an animal is a cow with high levels of the virus in its blood, for instance, is assumed to be able to infect other animals.

ECONOMIST: Foot-and-mouth disease

An electric motor revolving up to 10, 000 times a minute pushes an incompressible fluid around the Abiomed heart, and that fluid, in turn, pushes the blood first to the lungs to be oxygenated, and then around the body.

ECONOMIST: A promising new artificial heart wins regulatory approval