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Table 6 Comparison of complexity, hands on and total time involved in performing direct ZN, Magnetic bead and concentrated FM.

From: Feasibility of magnetic bead technology for concentration of mycobacteria in sputum prior to fluorescence microscopy

  Direct ZN Concentrated FM Magnetic bead-FM
  1. Label slides 1. Label slides 1. Label slides
  2. Transfer sputum using applicator and prepare smear 2. Transfer sputum to centrifuge tube 2. Attach adhesive wells
  3. Air dry 3. Add decontamination agent and mix 3. Add bleach solution to sputum
  4. Heat fix 4. Incubate 4. Incubate
  5. Transfer slides to staining rack and add stain 5. Add buffer to 50 ml mark 5. Add capture buffer, Magnetic bead and decon agent to tubes
  6. Rinse with water and drain 6. Load centrifuge 6. Add thinned sputum to capture tube
  7. Add decoloriser 7. Centrifuge 7. Incubate
  8. Rinse with water and drain 8. Unload, pour off supernatant and suspend pellet 8. Add suspension to wells, wash and remove water from wells
  9. Add counterstain 9. Make smears 9. Remove wells
  10. Drain and rinse with water 10. Air dry 10. Air dry
  11. Blot back of slides with tissue 11. Heat fix 11. Heat fix
  12. Air dry 12. Transfer slides to staining rack and add stain 12. Transfer slides to staining rack and add stain
  13. Examine slides under microscope 13. Rinse with water and drain 13. Rinse with water and drain
   14. Add decoloriser 14. Add decoloriser
   15. Rinse with water and drain 15. Rinse with water and drain
   16. Add counterstain 16. Add counterstain
   17. Drain and rinse with water 17. Drain and rinse with water
   18. Blot back of slides with tissue 18. Blot back of slides with tissue
   19. Air dry 19. Air dry
   20. Examine slides under microscope 20. Examine slides under microscope
Hands on time (mins)* 34.0 48.5 48.7
Total time (mins)* 74.6 146.6 139.5
  1. * Hands-on time and total time were estimated based on 3 batches of slides prepared (8-10 slides per batch). These times excluded examination times.