Pulse-Chase Labeling Kinetics Simulator

This page uses JavaScript to simulate the pulse-chase labeling kinetics of intermediates B, C and D in the metabolic scheme shown above. The JavaScript language is supported by Netscape Navigator and Microsoft Internet Explorer 3.0 or above. If you are using a JavaScript-compatible browser, try varying the pool sizes and fluxes to determine how this influences the labeling patterns. Note than when the rate of synthesis exceeds the rate of utilization, the pool will expand with time. When the rate of utilization exceeds the rate of synthesis, the pool will deplete with time. If a pool becomes zero during the time-course, the simulation will terminate before completion!

Starting values [values should not exceed 6 characters in length]:

Enter A1: (Precursor isotope abundance during the pulse (atom %))
Enter A2: (Precursor isotope abundance during the chase (atom %))
Enter B1: (Starting isotope abundance of pool B (atom %))
Enter B2: (Starting pool size of pool B (nmol.gfw-1))
Enter B3: (Rate of synthesis of pool B (nmol.min-1.gfw-1))
Enter B4: (Combined rate of utilization of pool B (nmol.min-1.gfw-1))
Enter C1: (Starting isotope abundance of pool C (atom %))
Enter C2: (Starting pool size of pool C (nmol.gfw-1))
Enter C3: (Rate of synthesis of pool C (nmol.min-1.gfw-1))
Enter C4: (Combined rate of utilization of pool C (nmol.min-1.gfw-1))
Enter D1: (Starting isotope abundance of pool D (atom %))
Enter D2: (Starting pool size of pool D (nmol.gfw-1))
Enter D3: (Rate of synthesis of pool D (nmol.min-1.gfw-1))
Enter D4: (Combined rate of utilization of pool D (nmol.min-1.gfw-1))
Enter time scale of the labeling simulation: (Time (min))
Enter time at which chase begins: (Time (min))

To disable the chase function, enter a "time at which chase begins" which is greater than the "time scale of the labeling simulation". After entering starting values (inputs), click the Calculate button. Simulated values will then be displayed in the text boxes below. The Calculate button can be reused repetitively after modifying input values.

Computed time-courses of isotope abundance (atom %) and pool size (nmol.gfw-1):

With certain browsers (e.g. Internet Explorer 3.0), the values displayed in the text boxes above are double-precision floating-point (e.g. 0.019995 may be displayed as 1.9995E-02). Thus, it may be necessary to use your mouse to highlight certain text boxes to view the full double-precision floating-point notations for values of less than 0.1. Errors resulting in script termination will occur when inputs are entered as text rather than as numerical values. Upon encountering such errors it may be necessary to "Refresh" the page.

Last update: 01/12/99
Author: David Rhodes