Tyrosinemia is a hereditary inborn error of metabolism that causes liver disease in infancy.  Affected persons commonly develop cirrhosis of the liver and will eventually require a liver transplant to survive.

Astoria-Pacific’s SPOTCHECK Tyrosine test is used as an aid in screening for hypertyrosinemia due to decreased levels of p-hydroxyphenylpyruvate oxidase (p-HPPA oxidase) activity in newborns.  This is most frequently seen as a transient low enzyme activity due to late maturation of the enzyme in newborns resulting in the temporary elevation of both tyrosine and phenylalanine in the blood.

Tyrosine Continuous Flow System

The SPOTCHECK Analyzer automates the measurement of galactose in the newborn’s blood sample by first hydrolizing galactose-1-phosphate to simple galactose using alkaline phophatase.  The total galactose is then oxidized by NAD in the presence of galactose dehydrogenase to form galactonoactone and NADH.

Positive Attributes of Instrumentation and Method:Semi-quantitative resultsNo operator attendance is required after loading sample plateModular system for easy maintenanceLarge capacity autosamplerSame day turnaround of resultsTotally automatic – no transfer of sample or reagents from one microtiter plate to another.Sample throughput is approximately 90 samples per hour.Can be run simultaneously with Total Galactose and Phenylalanine assaysPrepared reagents are stable for at least 14 days

Reagent Prep:
The SPOTCHECK Tyrosine 50 hour Reagent Kit contains all necessary reagents required for analysis and will provide approximately 50 hours of analyzer run time.  The approximate number of actual samples analyzed per kit is conservatively 2500.  All reagents are pre-weighed, color coded, and have a 2 year shelf life (with refrigeration).
Sample Prep:

  1. Punch one 1/8″ spots into microtiter filter plate.
  2. Add buffer for sample elution and shake for 30 minutes.
  3. Filter samples into round bottom microtiter plate.
  4. Place the sample plate on the auto-sampler.

Automated Steps:

  1. Sampler delivers calibrants, controls and samples to the cartridges
  2. Online incubation
  3. Online reagent addition
  4. Fluorometric detector measures fluorescent compound when tyrosine in a sample reacts with 1-nitros-2-naphthol.

Tyrosine Continuous Flow Brochure