laboratory diagnostic - hematology - Porphyrins - stool, Stool sample. Store away from light. DIET: within 72 hours prior to the assay, avoid consuming green vegetables and rare red meat.Advise the patient to store faecal samples in a refrigerator before sending to the laboratory. Result is released in 10 days if sample is positive, spectrophotometry, ssso, todylaboratories®, bmn, code L16LD1748