By: Don Penven
Note: Dischaps is the name of a product line manufactured by Sirchie Finger Print Laboratories. It refers to the type of packaging for a series of different chemical reagents. This packaging refers to DISsposable CHemical Applicators.
DISCHAPS™ packaging virtually eliminates the possibility of contamination of chemical reagents, and it dramatically increases shelf life. Reagents are contained within easily crushed glass ampoules. The ampoules are then sealed inside tough, flexible polyethylene dispenser tubes.
Blood DISCHAPS™ applications rely on using the contact method of testing—that is, a few drops of ethyl alcohol or distilled water (See Technical Information Bulletin) are placed on a strip of filter paper, and the wet filter paper is pressed against the suspected stain. The DISCHAPS™ reagent is then applied to the filter paper, thus preserving the original evidence stain.
PHENOLPHTHALEIN DISCHAPS™ (DCB100)
Note: Phenolphthalein reagent requires that ethyl alcohol be used to wet the filter paper during the contact stain lifting method.
Blood causes a Pink stain in just a few seconds. This reagent is considered by many field crime scene technicians to be one of the most reliable presumptive tests for the presence of blood because of its non-reaction to plant materials. Sensitivity=1:500,000.
Phenolphthalein reagent reaction to blood
LEUCO-MALACHITE DISCHAPS™ (DCB200)
An intense Blue/Green color reaction in 3 seconds is presumptive evidence that
blood is present. Sensitivity (1:10,000).
Leuco-malachite Reaction
LUMINOL DISCHAPS™ (DCB300)
Luminol reagent requires a darkened area for observation. This is the ideal reagent for
“aged” or invisible blood stains. In fact, the older the stain, the brighter the Blue/
White color reaction (within five seconds). Sensitivity: 1:100,000.
Luminol Reaction
For more specific instructions for use of the Dischaps Blood Test Reagents, you may download the Technical Information Bulletin <===
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