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 (11) Fluid (3) (-) RBCs (1) Serum or Plasma (11) Tissue (3) Urine (8) Test Area Exposure (1) Test Category (-) Biomarkers (1) Metals/Elements (4) Test Sub-Category Other (1) Test Test Name 4235R Sulfhemoglobin, RBCs