Related Experiment Video
Updated: Sep 22, 2025

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Benzidine color-crystal test; modified test to confirm the presence of blood stain
1State Forensic Science Laboratory, Jaipur 302016, Rajasthan, India.
Abstract:
In this study, author presented a color-crystal test, to confirm the presence of blood stain. In this test, blue colored micro-crystals were observed in case of positive blood sample. Since author included same reagents used for primary benzidine color test, hence in positive samples, used reagent impart blue color to the crystals and aid in proper visibility to the developed micro-crystals, observed under 20x and 40x magnification.
Related Concept Videos
Differential Staining Technique
Simple Staining Technique
Fixation and Sectioning
The simplest type of preparation is the wet mount, in which the specimen is placed in a drop of liquid on the slide. A liquid specimen can be directly deposited on the slide using a dropper. Solid specimens, such as skin scraping, can be placed on the slide before adding a drop of liquid to prepare the wet mount. Sometimes the liquid is simply water, but stains are often added...
Effects of EDTA on End-Point Detection Methods
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a...
Special Staining Techniques

