(5) Bilirubin Flashcards
Principle: Van den Berg reaction
* Performed at pH near 1.0
EVELYN & MALLOY
Coupling accelerator for B1
Methanol
o Diazo reagents for B2
✓ Diazo A: 0.1% sulfanilic acid + HCl
✓ Diazo B: 0.5% sodium nitrite
✓ Diazo blank: 1.5% HCl
Final rxn for E&M:
o Pink to purple azobilirubin (w/ maximal absorption @ 560nm)
Disadvantage of methanol:
causes ppt of proteins in
sample leading to turbidity
- Popular technique for discreet analyzers (like architect etc.)
- More sensitive, thus, widely used
- Safer due to neutral pH
JENDRASSIK & GROFF
Main reagent of JENDRASSIK & GROFF
Diazo reagent
JENDRASSIK & GROFF accelerator
Caffeine Sodium Benzoate
JENDRASSIK & GROFF buffer
Sodium acetate
terminates the accelerator & destroys excess diazo reagent
Ascorbic acid:
provides alkaline pH after
addition of ascorbic acid
Alkaline tartrate solution
Final rxn JENDRASSIK & GROFF
blue azobilirubin (measured at 600nm)
Ehrlich’s Reagent:
p-dimethylaminobenzaldehyde (p-
DABA)
1 Ehrlich unit = 1mg Urobilinogen
Double Collection method (2 blood samples are collected)
ROSENTHAL WHITE method
Spx collection for Rosenthal white
o 5mins after BSP administration
o 30mins after BSP administration