G6PD deficiency is an inherited condition in which the body is deficient in the enzyme glucose-6-phosphate dehydrogenase, or G6PD, which helps red blood cells (RBCs) function normally. This deficiency can cause hemolytic anemia, usually after exposure to certain medications, foods, or even infections.  Early detection of this enzyme deficiency can aid in the diagnosis and treatment.

Glucose-6-phosphate dehydrogenase is the initial enzyme in the hexose monophosphate pathway of glucose metabolism. In the SPOTCHECK® method, enzyme activity is measured by observing the fluorescence produced after NADP+ is reduced to NADPH when glucose-6-phosphate is present as a substrate. As G6PD catalyzes the oxidation of glucose-6-phosphate to 6-phosphogluconate, NADP+ is reduced to NADPH, which is measured by a fluorometer. The amount of NADPH produced is proportional to the G6PD enzyme activity in the sample. Maleimide, an inhibitor of 6-phosphogluconate dehydrogenase activity, is added to prevent the conversion of 6-phosphogluconate to ribulose-5-phosphate and additional production of NADPH.

G6PD Continuous Flow System

Positive Attributes of Instrumentation and Method:

  • Semi-quantitative results
  • No operator attendance is required after loading sample plate
  • Modular system for easy maintenance
  • Large capacity autosampler
  • Same day turnaround of results
  • Totally automatic – no transfer of sample or reagents from one microtiter plate to another.
  • Throughput is about 90 samples per hour.
  • Can be run simultaneously with Total Galactose and Phenylalanine assays

Reagent Prep:
The SPOTCHECK G6PD 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” spot into microtiter filter plate.  Plasma or serum may also be analyzed.
  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 cartridge
  2. Online reagent addition
  3. Online dialyzer to filter out interferences
  4. Online incubation
  5. Flurometric detector measures NADPH which is proportional to the G6PD enzyme activity in the sample

G6PD Continuous Flow Brochure PDF