The Sample From The Interior Showed No Starch

deionizedIN ORDER to determine the nature of the adhesive residues, individual paper fiber samples of the edge and interior were taken from the reverse of the tissue.

These were stained with potassium iodide and examined under the microscope. While confirming the presence of starch, the sample from the interior showed no starch, The sample from the periphery showed a positive reaction. Another method had to be found, since previous washing had not removed the starch adhesive residues and the wetted sheet was enzymes are not particularly difficult or hazardous to use.

The product literature indicates the optimum conditions for ‘αAmylase’ to be a pH of 9 and at 37°-40°, and suggests the use of sodium phosphate as a buffer to stabilize the solution at a neutral pH. We were reluctant to use this buffer since we are not convinced it can be satisfactorily rinsed from the paper after use. We preferred to neutralize the solution with calcium hydroxide, a chemical we often use as a deacidification agent. Notice that no adverse effects been noted on the action of the enzyme by this substitution.

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The print was thence bathed in deionized water to dissolve the starch. Upon removal from this bath, the margins of the print were flooded with ethanol to inactivate the enzyme and the print was allowed to air dry.after air drying, the interior of the sheet remained quite puckered, the borders appeared free of adhesive and quite relaxed. The print was therefore bathed in deionized water to dissolve the starch. Upon removal from this bath, the margins of the print were flooded with ethanol to inactivate the enzyme and the print was allowed to air dry.

Consequently, after air drying, the interior of the sheet remained quite puckered, the borders appeared free of adhesive and quite relaxed.

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