The TrueNAT laboratory should maintain a document/ records of Truelab and Trueprep usage and maintenance using the logs and/ or checklist. This helps to:

• Maintain record of the health of the instrument for user and manufacturer
• Reduce risks of accidents due to faulty instrument
• Identify user re-training needs
• Reduce instrument downtime.

Representative documents to maintain record for use and maintenance are shown in table 1(A) - (B) and figure below.

Like any other laboratory instrument, the TrueNAT machine needs a periodic maintenance.

Maintenance of Truelab and Trueprep instruments includes:

• Cleaning the instrument
• Disinfecting the surfaces
• Cleaning the spillages
• Discarding the used consumables
• Calibrations
• Replacement of parts
• Flush protocol
• Data backup
• Troubleshooting errors, alerts, warning messages

Frequency of maintenance:

The limitations of TrueNAT Assays are:

“Indeterminate” result on completion of the test run with TrueNAT MTB-Rif Dx means Polymerase Chain Reaction (PCR) melting temperature (Tm) values did not meet the requirements for Rif resistance determination.

Implications

• The initial result of Mycobacterium tuberculosis “DETECTED’ (Truenat MTB) is the bacteriological confirmation of TB.
• TrueNAT MTB Rif Dx did not provide information on resistance to Rif.

Troubleshooting TrueNAT MTB Rif Dx “Indeterminate”

On completion of test run, the Test Result Screen displays the results for:

• Detection of Mycobacterium tuberculosis (Truenat MTB)
  • “DETECTED” for Positive result, Cycle Threshold (Ct) value, Colony Forming Units per milliliter (CFU/ ml)
  • “NOT DETECTED” for Negative result
  • “Valid”/ “Invalid” for test validity based on amplification of Internal Positive Control (IPC)
  • “Error” for test failure

Truenat MTB Assay results are visualized:

• During testing
• Completion of test

Test Status Screen (Figure 1)

Results visualization during testing include:

Procedure

Equipment and reagents

• Truelab Uno/ Duo/ Quattro Real Time Quantitative micro–PCR analyzer
• Truenat MTB micro-PCR kit
• Truenat MTB Rif micro-PCR kit
• Truepet fixed volume (6 μl) precision micropipette

Amplification and detection of Mycobacterium tuberculosis (MTB)

The extra-pulmonary samples (Non-sputum) can also be processed and used for MTB and Rif diagnosis using Truenat. The processing of various extra-pulmonary samples is described below.

Reagents required:

Trueprep AUTO MTB Sample Pre-treatment Pack for sample processing

• Reagents stable for two years (2-40°C) or one month (temperatures up to 45°C)
• Avoid exposure to light or elevated temperatures
• Do not freeze

Steps in processing of non-sputum samples

Equipment and Consumables

• Trueprep AUTO v2 Universal Cartridge Based Sample Prep Device
• Trueprep AUTO v2 Universal Cartridge Based Sample Prep Kit

Steps in DNA extraction (Molbio Trueprep Auto Universal Cartridge Based Sample Prep Device)

1. Wear gloves, mask.

2. Insert the plug-in connector to attach the reagent pack to the Trueprep device (Figure 1).

Samples collected for TrueNAT tests are tested immediately (if collected at TrueNAT facility) or transported on the same day to nearest linked TrueNAT facility.