Marina Seabright, Rapid Banding Technique for Human Chromosomes’, 1971 was the topic of an earlier blog post.
Here I present: Marina Seabright, Rapid Banding Technique for Human Chromosomes’, 1971, PART FIVE (5).
INTRODUCTION.
The double-helixes (two spiral-springs) of the Watson-Crick DNA molecule can be thought of as a coupled slinky (two spiral-springs).
The slinky is modeled by N identical massless springs with spring constant d and masses m in between as shown in figure 2. A given mass experiences forces from the two neighboring springs leading to the following equation of motion
Marina Seabright, Rapid Banding Technique for Human DNA’, 1971 use Giemsa stain intercalation as DNA binder (shown BELOW). The Giemsa stain results in black, gray & white bands in the chromosomal DNA .
1. AT/AT pairs stain BLACK.
2. GC/GC pairs stain WHITE.
3. AT/GC pairs stain GRAY.
The double-helixes (two spiral-springs) of the Watson-Crick DNA molecule can be thought of a coupled slinky (two spiral-springs). This viewpoint is adequate to explain the banding pattern in the Marina Seabright stain method of chromosomal DNA. A coupled slinky (two-spiral springs) is a mathematical concept used in teaching mechanical ideas.
