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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.