Truenat tests use Internal Quality Control to assess test validity using Internal Positive Control (IPC).

• The cartridge contains pre-loaded IPC.
• IPC is part of the full process control.
• IPC undergoes all processing steps along with specimen from extraction to amplification.
• IPC assesses the validity of the test run from sample processing to result and is illustrated in following figures (Figure 1(A) and Figure 1(B)).

Truenat cartridges are components of Trueprep AUTO v2 Universal Cartridge Based Sample Prep Kit. As shown in the figure below, each cartridge is:

• Used with Trueprep Device for DNA extraction and purification
• Disposable
• Single-use
• Preloaded with Internal Positive Control.

Truenat cartridges are used with Trueprep devices for DNA extraction and purification. The components of the cartridge are illustrated in the following figure and include:

TrueNAT MTB and TrueNAT MTB Rif Dx Assay are intended to be used for detection of Mycobacterium tuberculosis bacteria (for TB diagnosis) and to detect resistance to rifampicin (Rif), respectively.

Positioning of TrueNAT MTB and TrueNAT MTB Rif Dx Assay

TrueNAT MTB and TrueNAT MTB Rif Dx Assay are suitable as point-of-care tests for use in peripheral laboratories and microscopy centres due to the following operational features:

Ensuring accurate sputum microscopy results is paramount to maintain optimal sensitivity and specificity of sputum microscopy.

In this regard, External Quality Assurance (EQA) is an important aspect of the National TB Elimination Programme (NTEP) Laboratory Network. Different levels of EQA activities are undertaken to ensure that the system follows a standard protocol and remains efficient. The timely completion of EQA activities is important.

Fluorescence Microscopy is a newer and better type of microscopy where the TB bacteria are stained using a fluorescent dye using the property of Acid Fastness. The dye will fluoresce when illuminated by UV light. When the UV light source is an LED Lamp, it is called LED fluorescent microscopy.

Here the bacilli appear as slender bright yellow fluorescent rods, standing out clearly against a dark background, as can be seen in the figure below.

The procedure will be the same for Laboratory Technician (LT) at Culture and Drug Susceptibility Testing (C & DST) lab for preparation and validation of reagents.

Each laboratory should have a Quality Control (QC) slide examination register.

At the District level the Senior TB Laboratory Supervisor (STLS) should record the QC slides (positive and negative) results in the register kept after preparation of each batch of reagents at the District TB Unit.

While doing sputum smear microscopy for presumptive TB patients, it is essential that the correct specimen part is tested for microscopy.

During smear preparation, each Laboratory Technician (LT) should identify a part of specimen that is either mucoid or purulent or mucopurulent, instead of thin saliva (Figure).

Acid-fast Bacilli (AFB) tend to be more in the purulent part of the smear.

Figure: Best Portion Selection for Performing Sputum Microscopy

As Tuberculosis (TB) infection spread in the form of droplet infection, healthcare workers in the TB laboratory setting need to follow standard safety precautions to prevent themselves from getting the TB infection.

Some of the safety precautions in the TB laboratory setting are as follows: