A Generalized Method for the Computer Analysis of Lipoprotein Distributions

Although it is possible to read schheren films with automatic scanning devices (13) that produce data in a form suitable for direct use on a computer, we have elected to use a simple manual procedure in preparing analytical ultracentrifuge data for computer analysis. This not only reduces cost in the developmental phase of the computer solution, but also allows greater control over such reading problems as accurate sens- 

To make the necessary measurements, vertical parallel lines are drawn on the tracing connecting the two marks at each subdivision the height of the schlieren curve at each subdivision is measured with a machine divider ruler (Paragon 56 3278, Keuffel Esser Co., Hoboken, New Jersey), and transcribed onto a prepared data form. The form also contains spaces for such data as identification number, run type, Spinco E machine used, frames read, dilution from the original sample, location of the major component, density and temperature of the run, constants that require redefinition for the analysis of the run, and a brief descriptive statement that can serve to further identify the run. Most of this information can be optionally left blank if it is not applicable, and the program will automatically substitute the standard values or options. 

Calculation time for the 7094 program varies somewhat, depending on machine factors such as tape positioning and on the extent of the calculations desired but in general, the calculation time (including input and output) for a low-density film, consisting of 29 components, is between 0.01 and 0.02 minute. Time required to load the program itself into the computer memory is approximately 0.35 minute. 

In order to discuss the details of these calculations, we define the 

All lower case notations refer to the n standard intervals. For the 2n -f- 1 intervals of the expanded integral curve, the symbols are Ft, Xt, Q, and C , where F consists of the table of values fo, /i , fi, fz , fz. 

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