VMD 511: Animal Welfare, Ethics and Jurisprudence (2+0)

CHEMICAL EXAMINATION

Benzidine test

• Press piece filter paper over stain.
• Add few drops of 10% benzidine sol in glacial acetic acid.
• Add few drops of fresh, acti 3% hydrogen peroxide.
• Green or blue colour positive.
• Sensibility – 1: 200,000.
• Not specific for blood.
• Most oxidising agents like permanganate, chromates, bichromates etc.
• Give strong reaction with our addition of H₂O_2.
• Positive result big pas, secretion of throat and nose by plant juices, by commercial formalin, fly excretion.

Phenolphthalein test

Solution preparation

• Phenolphthalein – 18 ml
• Sodium hydroxide- 20 pm
• Distilled water – 200ml
• Mix phenolphthalein and sodium hydroxide in distilled water and boil it under a reflux condenser.
• Add 20gmof granulated Zinc (20 to 30 mesh) while boiling.
• Boiling continued until solution become colorless

Procedure

• 1 to 2 ml of saline suspension of blood stain in a test tube.
• Boil it for ½ minutes to destroy any oxidases.
• Cool it and add 5 drops of phenolphthalein reagent and followed by some drops of 3% H₂O_2.
• Pink colour develop in position cases.
• Colour lasts no longer the 3mts.
• Sensitivity 1: 1,000,000.
• Not specific for blood.
• Direct oxidising compound copper, potassium ferricyanide and nickel – positive reaction.

Leucomalachite green test

Reagent

• Leucomalatitie green – 18 m
• Acetic acid- 100ml
• Distilled water – 150ml
• Add one drop of the reagent on the stained filter paper
• Lease it for 10 seconds
• one drop of H2O2
• Green colour develops – if blood.
• More sensitivity – not commonly used.