A staple cartridge for use with a surgical stapler and surgical stapling systems are disclosed. The staple cartridge comprises a cartridge body having a tissue-contacting surface. One or more light emitting diodes (LEDs) are positioned at the edges of the tissue-contacting surface. A plurality of staple drivers is located within the cartridge body each supporting a staple.

A composition may include, in dry form: (a) nigrosin; (b) wheat flour; and (c) whole egg. Such compositions may be used for production of test soil for assessment of the cleaning action of cleaning devices. Methods of producing a test soil for assessment of the cleaning action of cleaning devices for cleaning of vessels for human egesta, e.g., of washer-disinfectors, including dissolving the composition in an aqueous medium. A test soil may include the constituents of the composition in an aqueous medium, and such soils may be used for assessment of the cleaning action of cleaning devices. A method may assess the cleaning action of cleaning devices for cleaning of vessels for human egesta.