The design, calibration, and operation of a source of controlled amounts of cyclic AMP (c-AMP) are described. Typically, 1.5 s pulses containing 10(10)-10(-12) molecules of c-AMP can be delivered to a region about 10 mum in diameter on an agar plate. The resulting concentration profiles are given as functions of distance and time. The diffusion coefficient of c-AMP in agar was measured to be 0.97 times 10(-5) cm2-s-1 at 21 degrees C. © 1975, The Biophysical Society. All rights reserved.
Cohen, M. H., Drage, D. J., & Robertson, A. (1975). Iontophoresis of cyclic AMP. Biophysical Journal, 15(8), 753–763. https://doi.org/10.1016/S0006-3495(75)85852-8