Evaluation of the performance and feasability of the fluorescein diacetate (FTA) vital staining method for follow up of Tuberculosis (TB) treatment

Feasibility Simple staining procedure, not time consuming (approximately 1.5 hours) Standard microscope equipped with LED cassette can be used for read-out Mean reading time for slides = 6.3 minutes (IQR: 5.4, 7.4) Limitations: 20°C freezer (storage of FDA stock solution: 25 mg/ml FDA in Aceton) 37°C incubator (maybe required) fading of fluorescein signal (within hours): • Stained smear need to be read shortly after preparation • Scanty-loaded AFB-sputum may be miss-read as “fluorescein-negative” • Challenge for implementation of reliable quality control measures