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(a) Sensor

Lead screw

Injector

Plunger

Syringe

Stirring

Outer shield

Reference cell Sample cell

Inner shield

Sensor

0.0

Molar ratio

mcal/sec

0.5 1.0 1.5 2.0 2.5

–15

–10

–5

0

–1.5

–1.0

–0.5

0.0

kcal/mole of injectant

(b) Time (min)

0 20 40 60 80 100 120 140

Fig 15.13Isothermal titration calorimetry. (a) Diagram of MicroCal ITC cell and syringe. A thermoelectric device

measures the temperature difference between the two cells and a second device measures the temperature

difference between the two cells and the jacket. The plunger is computer-controlled and injects precise volumes

608 Enzymes