LT-Microscopy & NAAT

The following are the measures to be kept in mind when adding immersion oil to the slide:

• Before adding immersion oil to the slide, ensure that the smear is facing upwards (Figure 1).

Figure 1: Slide should Face Upwards when Mounted on the Microscope Stage

The Tuberculosis (TB) Laboratory Register is a paper-based recording register kept in all National TB Elimination Programme (NTEP) laboratories for recording details of diagnostic services offered to TB patients referred from both private and public health facilities.

The register is maintained in the Designated Microscopy Centre (DMC). It is the only register used for recording the details of specimen smear examinations. The Laboratory Technician (LT) is responsible for maintaining and updating the laboratory register.

Guidelines for Laboratory Cleaning

PPE refers to physical barriers which are used alone or in combination to protect an individual's mucous membranes, airways, skin and clothing from contact with infectious agents, hazardous material, conditions or processes.

Good laboratory practices help to maintain biosafety in TB lab settings. However, it is good to keep in mind that:

• NOTHING can totally eliminate the safety risk associated with the TB laboratory.
• Good laboratory practices with an emphasis on biosafety, significantly reduce the risk of laboratory-acquired infection.
• Specialized equipment aids good laboratory practice but does NOT replace it.

Good Laboratory Practices

Disposal of biohazardous waste is essential to prevent contamination and possible infection of those handling the infected specimens.

At the end of each day, Cartridge-based Nucleic Acid Amplification Test (CBNAAT) laboratories generate contaminated material such as:

• Used sputum containers
• Used cartridges
• Transfer pipettes.

All used materials should be considered contaminated.

It is essential to follow biosafety protocols while handling specimens and cartridges. This will prevent anyone handling the specimens and cartridges from getting infected.

General Biosafety Requirements for CBNAAT

Cartridge-based Nucleic Acid Amplification Test (CBNAAT) is a low-risk procedure and requires the same level of precautions, like those used for direct Acid-fast Bacillus (AFB) sputum smear microscopy:

The annual maintenance protocol for the Cartridge-based Nucleic Acid Amplification Test (CBNAAT) instrument involves calibration of the machine. 

Calibration:

It is important to adhere to the manufacturer's installation guide for optimal performance of the Cartridge-based Nucleic Acid Amplification Test (CBNAAT) machine. This guide should be kept in the laboratory. It is important to thoroughly read the instalment steps given in the brochure supplied with the machine.

Strict monitoring of these criteria should be carried out by the laboratory personnel:

Maintenance of the CBNAAT instrument is an essential activity to be performed in the laboratory setting and involves:

Preventive Maintenance Tasks

• Performed regularly by the user
• Ensure the good performance of the system
• Avoid problems of malfunction

Need-based Maintenance Tasks

• Performed in specific situations
• Performed or guided by manufacturer representatives

Frequency-based Tasks for the CBNAAT Instrument