The Experiment Section
This section of the main form is organized to contain information that is particular to particular experiments. Since samples and buffers may be common to many experiments, they are saved in their own sections. Saved experimental data can be retrieved by choosing the name of the experiment from the list in the combo box at the top of the form. When experiment data is retrieved, buffer and sample data is automatically retrieved at the same time.
There are three buttons to choose the method Sednterp uses to determining the molecular weight of the sample. Pressing a button chooses the method and highlights the button with a green underline. If the Exact Molecular Weight button is chosen, direct user entry of a known molecular weight in the Mr text box is possible. If the From Sigma button is chosen, Sednterp is set to compute the molecular weight from a sedimentation velocity experiment. Since vbar, rho, and temperature have automatic defaults, a quick answer is obtained by entering sigma and RPM. If Sednterp does not have enough information to compute the molecular weight, a stop sign will appear over the Mr box. If the From Composition button is active, the molecular weight is computed by a protein composition entered on the Sample Composition form. Pressing the From Composition button accesses this form and the subsidiary information (sample charge, absorption spectra, hydration) available from the form.
The Sed Equilibrium subsection contains text boxes to enter the temperature, sigma, RPM from experiment. Information is entered by typing in values.
The Sed Velocity subsection contains text boxes to enter the temperature, concentration, and sedimentation coefficient from a sedimentation velocity experiment.
The Results subsection displays the buoyant molecular weight, the computed minimum radius of a sedimenting species modeled as an anhydrous sphere, and the sedimentation coefficient corrected to 20 degrees C in pure water.