Test Order Name - AFB (Acid Fast) Smear
Synonym(s) - Screening for the presence of acid-fast bacilli in a clinical specimen
Methodology - Acid Fast Fluorescent Stain (Auramine-Rhodamine) and Microscopy
Acceptable Specimen Type(s) for Testing - Sputum (expectorated or induced); urine (first morning collection)
Transport / Collection Medium - Sputum: sterile collection cup; urine: large sterile plastic container
Storage and Preservation of Specimen - Refrigerate at 4°C after collection and deliver to the laboratory within 3 days.
Minimum Volume Required - 3 to 10 milliliters (1 milliliter is acceptable) of sputum; greater than 50 milliliters of urine
Additional Collection Instructions - It is ideal to have at least three consecutive sputum specimens obtained, each collected within 24 hours and at least one being an early morning specimen. Have the patient rinse mouth with water before collecting the specimen to minimize contamination with food particles, mouth wash, or oral drugs which might inhibit the growth of mycobacteria.
Additional Required Information - Label specimen with patient name, date of birth, medical record number and date of collection; Label requisition with patient name, date of birth, address, medical record number, gender, date of collection, submitter name, requesting clinician, specimen source and test request.
Send Out? - No
Turnaround Time - 24 hours
Testing Restrictions - Rejection Criteria: Leaky specimens; No label on the specimen; Requisition and specimen labels do not match; Quantity not sufficient for testing; Specimen is too old for testing; Specimen was not stored properly
Limitations / Notes / Disclaimer - Recovery of mycobacteria species is dependent upon quality of specimen and collection. It is critical to follow the collection procedure to ensure inhibitory substances are removed from the mouth