Templates

There are two general kinds of templates for the SHArK project: pipetting templates, and printing templates.

Binary Mixtures and the Line
Suppose you wanted to mix two pure subtances in all possible ratios (known chemically as stoichiometries). The most direct way to do so would be to form a line segment, where the beginning and ending points represented each pure component. As you move along the line from one end to the other, the composition would continuously and gradually change from one pure component to the other, as shown at right using two subtractive primary colors, magenta and cyan.

Ternary Mixtures and the Triangle
For a ternary composition (that is, a mixture of three components), a triangle may be used to lay out the component gradients. Such a gradient is essentially a ternary plot. The vertices of the triangle then represent the three pure components, and the edges represent binary mixtures of the connected vertices. Such an arrangement is depicted at right, using all three primary subtractive colors.

Quaternary Mixtures and the Tetrahedron
Taking into account the ideas presented so far, extending the number of components to four necessitates the use of a tetrahedron, again with each vertex representing a pure component, and each edge a binary mixture. Again, the faces comprise the possible ternary mixture, and the volume of the shape comprises the possible quaternary mixtures.

Pipetting Templates
Pipetting templates have generally been designed individually at each institution, with little consistency between designs. It is desirable to come up with a standardized format for pipetting, although this has not yet been accomplished. In the meantime, this list of templates shall serve as inspiration for concepts to be considered when such a time shall come that an official template should be adopted.

The Texas 6 Spot


The template shown at right mimics the gradient pattern of the printing templates. The pattern models two faces of the tetrahedron as a 6x6x6 triangle. Such a design is inefficient because of the high degree of redundancy (e.g. each internal standard occupies three dots, and each "edge" of the tetrahedron is present in duplicate between the complementary plates.) As well, the template is too ambitious; when pipetting, there is no particular reason to use the "unfolded tetrahedron" design. The reason for its use in printing is simply because the printer has the inbuilt capability to print four different channels simultaneously. Pipetting does not allow for such an advantage.