HotAIR - The Size of a Jelly Molecule as Estimated by Jelly Electrophoresis


The Size of a Jelly Molecule as Estimated by Jelly Electrophoresis

by Gregory J. Crowther
Department of Physiology & Biophysics, University of Washington, Seattle, Washington

Figure 1. In jelly electrophoresis, the electrophoresis box doubles as a transparent toaster, allowing data to be generated and "cooked" simultaneously. (NOTE: the author’s camera lens was covered with a thin layer of jelly.)

Despite the importance of jelly as a sandwich ingredient, its molecular structure remains poorly understood. We therefore attempted a preliminary characterization of the jelly molecule using a novel technique we call "jelly electrophoresis."

Jelly electrophoresis is a methodological cousin of gel electrophoresis, in which a molecule’s size is estimated from its speed of travel through a porous matrix. In the case of jelly electrophoresis (see Figure 1), the matrix, in addition to being porous, is generally edible. Details are presented below.


Three samples were placed in separate "lanes" atop a slice of multigrain bread: a tablespoon of jelly, a tablespoon of water, and a small piece of turkey (see Figure 2B). The samples were allowed to migrate vertically through the bread while the experimenter ate lunch, a period of approximately 20 minutes. The bread was then removed from the experimental apparatus for further analysis (see Figure 3).

The water and the turkey, being of known composition, served as molecular weight markers against which to compare the jelly. The molecular weight of water is 18, while turkey is composed primarily of actin and myosin filaments of molecular weight 42,000 and 520,000, respectively.1

Figure 2. Raw data for (A) gel electrophoresis on a mouse muscle extract and (B) jelly electrophoresis on a slice of multigrain bread. Note the slight migration of the jelly down from the top of the bread.


The distances traveled by the samples through the bread are reported in Table 1. The molecular weight marker results were used to construct the standard curve shown in Figure 4, which the author neglected to send to the editor. Based upon this curve, the migration distance of the jelly (0.2 cm) indicates that its molecular weight is approximately 90,000.


Jelly molecules are surprisingly large. Nevertheless, they migrate through bread at a measurable speed -- roughly 0.6 cm/hour, permitting them to pass all the way through a 1.5-cm-thick slice of bread in 2.5 hours. To prevent such behavior, a "crustless sandwich" design, in which the jelly is surrounded by a layer of impenetrable peanut butter,2 should be employed whenever possible.

Figure 3. A post-electrophoresis piece of bread. (NOTE: the author’s camera lens was covered with a thin layer of jelly.)


TABLE 1: the application of jelly electrophoresis to some common kitchen reagents.
Sample -- Molecular weight -- Distance traveled
water -- 18 -- 2.6 cm
turkey --x -- x
actin -- 42,000 -- 0.0 cm
myosin -- 520,000 -- 0.0 cm
jelly -- ???-- 0.2 cm



1. Muscle Contraction, C. Bagshaw, 1993, London: Chapman & Hall.
2. For an example of this kind of device, see "Plucked From Obscurity: Crustless Sandwich," M. Tsipis, Annals of Improbable Research, vol. 8, no. 2, March/April 2002, p. 30.


M. Lambeth, D. Marcinek, E. Shankland, and R. Stuppard contributed and/or consumed materials used in this study.

This HotAIR feature first appeared in AIR VOLUME 8-ISSUE 4. For a complete list of strangely fascinating featured articles elsewhere on this web site, see What's New.