Immunology Diagnosis

There are serveral aproches to assess the fagocitic capacity of Leukocytes as well as the oxidative burst that occurs after fagocitosis

The traditional Nitro-Blue-Tetrazolium (NBT) test:

http://www.nlm.nih.gov/medlineplus/ency/article/003355.htm

It has been gradually substituted with more specific and better quantitative colorimetric assays:

Some of them still with the same chemical basis:

http://www.fardiag.com/uploads/pubblicazioni/app_182/3053%20FAGOTEST%20ing.pdf

http://www.cellbiolabs.com/phagocytosis-assays

Or, more latelly, flow-cytometric based methods could also be used to specifically quantify cells (granulocytes and monocytes) engulfing as well as degrading bacteria:

http://www.glycotope.com/immunodiagnostics/clinical-diagnostics-research-reagents

QUALITY CONTROL: you have specific proficiency testing offered by GECLID-SEI to asses the performance of the used technique:

http://www.geclidsei.uva.es/mod/resource/view.php?id=1767