Chromatography Game Intro

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You are head of the purification group of a small company selling enzymes for research. Most of your products have sales that are insufficient to justify research projects to optimize the purification schemes. Instead, general adsorbents are employed that usually purify enzymes quite well. There are many adsorbents from which to choose, and the capacities and resolving powers differ for various enzymes. Note that these adsorbents are quite expensive, but there is no relation between price and performance.

One of your products has been manufactured and sold in very small quantities for years. Suddenly you have a rush order for 40 grams, an amount that is far greater than you can make quickly with your old method. The implications for future sales and for developing an optimum process will not concern you yet; you are asked to fill this order fast. Any enzyme from test runs can be combined and sold with the main batches.

Six adsorbents are likely prospects for achieving purification of this enzyme. If you are lucky and can select a good one, there is no point in testing them all. There are no useful specifications on them because no one has ever evaluated properties with this enzyme.

You select from batches of partly purified enzyme. You may also rework chromatography fractions that do not meet the purity specification. A more pure feed stream means better operation of the chromatographic step, but with increased cost because of the previous losses.

The chromatograms show two other major proteinaceous impurities from which your enzyme must be resolved. Fractions of column effluent of over 95 per cent purity (the minimum specification for salable enzyme) are pooled and saved. Increased loading smears the chromatograms. In order to save time and money, you want to use larger column diameters and moderate loadings.

Solubilities of various proteins as functions of ammonium sulfate concentration were formulated in simple expressions and used to construct a plot to help you decide how to operate. Note that the yield of desired enzyme is zero until a certain concentration of ammonium sulfate is reached, and there is a peak followed by a decline in yield if too much is added.

Batches may be combined, and additional batches are created automatically from side fractions in the next purification step of column chromatography. You will discover that the peaks can spread and overlap with poor matches of column diameter and loading.

In response to the prompt for kilograms of liver, a small number doesn't provide much crude enzyme to work with. Several hundred kilos is too much. Ten or twenty kilos is reasonable as you are gaining experience, but you will need more later.

You are asked for the column diameter (in centimeters). A small column is okay for analytical work but too tiny for a big production run. Although today's columns can be quite large, this program has only a smaller range of column sizes available. The computer tells you the loading divided by the capacity of that resin. If this ratio is more than one, the column is overloaded and can give no separation. Initial choices of resin are strictly luck. You should experiment but with columns that are not very big because smeared chromatograms will tell you little. Study your results and continue making more batches or performing chromatography to accumulate the desired amount of pure enzyme.

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