Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) Spectrophotometry (SP) (1) Sample Type Blood (12) Fluid (4) (-) RBCs (1) Serum or Plasma (13) Tissue (4) Urine (7) Test Area Exposure (1) Test Category (-) Biomarkers (1) Metals/Elements (4) Test Sub-Category Other (1) Test Test Name 4235R Sulfhemoglobin, RBCs