AMPLIFYING PRECISION:
High-Quality Reagents for Multiplex Respiratory Assays
Point-of-Care (POC) Respiratory Testing
Point-of-care diagnostics for respiratory diseases has been a rapidly evolving field and the COVID-19 pandemic helped to accelerate the development and public uptake of point-of-care respiratory testing. Both immunodiagnostics on paper platforms and molecular diagnostics on microfluidic platforms have received particular attention for the development of POCT techniques (Science Direct LTD). However, developing POC multiplex assays for respiratory diseases is particularly challenging due to the potential for cross-reactivity between pathogens and the high sample complexity, with respiratory specimens often containing various types of cells, mucus, and other components which can interfere with the test, and affect assay accuracy.
Respiratory tract infections are the most common diseases affecting humans and the global respiratory pathogen testing market is expected to grow from US$3.1 billion in 2022 to US$4.2 billion by 2030. With the ongoing evolution of healthcare diagnostics to improve patient care and outcomes, POC testing methods for respiratory diseases is pivotal in facilitating early detection and effective management.
Meridian offers comprehensive solutions to meet your needs with both reagent solutions for rapid immunoassays and molecular tests using either qPCR or LAMP techniques. to meet your needs.
Diagnostic Assay Solutions for Top 3 Viral Infections
Influenza A/B
Influenza viruses are RNA viruses that are prone to antigenic drift and reassortment, which enables new strains of the virus to emerge each year. Diagnostic influenza tests include rapid influenza diagnostic tests (RIDTs), direct fluorescent antibody
stains, viral cultures, and molecular assays. The tests typically distinguish influenza type A from
influenza B, and can also identify influenza A subtypes. Rapid assays for influenza typically detect the nucleoprotein (NP) using swabs or samples of secretions taken from a patient’s nose or throat and the entire test can be performed at the point-of-care (POC). The results are rapid (under 30 minutes) however they may not be able to indicate which specific strain of flu the patient has. Rapid molecular assays are the preferred diagnostic tests because they can be done at the point of care, are highly accurate, and have fast results.
SARS-CoV-2
SARS-CoV-2 is a coronavirus responsible for the 2020 COVID-19 pandemic. Current diagnostic tests for the SARS-CoV-2 include molecular tests, antigen tests and serological tests. Molecular tests to detect viral nucleic acids are the ‘gold standard’ for detecting SARS-CoV-2 infection, but they can be time-consuming and generally require a laboratory or trained personnel. Immunoassays are less sensitive, but they offer rapid results. Most antigen detection assays use antibodies that recognize SARS-CoV-2 nucleocapsid protein as it is the most abundant viral protein. Spike protein has also been targeted, especially in assays that use alternative sample types such as saliva or nasal swabs that can be collected by an individual. The antibodies detect a conserved region N protein and they do not exhibit any cross-reactivity to influenza A/B, RSV or seasonal coronavirus strains.
RSV
Respiratory Syncytial Virus (RSV) is a common respiratory virus that usually causes mild, cold-like symptoms but can cause more serious problems such as bronchiolitis and pneumonia in babies and young children. RSV virus consists of three main proteins and the fusion protein (which is responsible for fusion to the host membrane) is the current leading target for diagnostic assays and the majority of vaccines and immunotherapies under development. Several different types of laboratory tests are available for the diagnosis of RSV infection including ELISA, rapid lateral flow, Direct Fluorescent Antibody Detection (DFA), neutralization assay and RT-PCR. Most clinical laboratories currently utilize EIA antigen detection tests, and many supplement antigen testing with cell culture or immunofluorescence assays to confirm diagnosis.
Antigens & Antibodies for Rapid Tests
Multiplex rapid lateral flow assays for respiratory infections such as the flu, COVID and RSV offer an efficient testing solution. However, due to differences in the viral strains, viral loads, and sample types, balancing high assay sensitivity and specificity can be complex, especially is the viruses share genetic or antigenic similarities, leading to potential cross-reactivity.
Meridian’s monoclonal antibodies for Flu A, Flu B, COVID, and RSV are designed for low cross-reactivity and high sensitivity, ideal for lateral flow rapid multiplex tests for COVID/FLU/RSV.
Enzymes & Master Mixes for Molecular Assays
Multiplex assays save time and resources, especially in point-of-care settings, by evaluating many targets at once in a single reaction, from just one sample. For respiratory infections that cause similar symptoms, multiplex testing is the only way to differentiate between diseases to start the correct course of treatment or care. However, multiplex tests are challenging to develop as the assay must detect the different targets to the same level of accuracy and sensitivity as a single test. Meridian specializes in enzymes and master mixes for RT-qPCR and RT-LAMP that designed for fast and sensitive amplification over a wide dynamic range. In addition, Sample-specific™ mixes for saliva assays enable direct detection from the crude patient specimen, without the need for extraction. The key difference in Meridian’s molecular reagents is their optimization for top performance in the presence of PCR inhibitors. By enhancing inhibitor tolerance of the mixes and enzymes, Meridian’s reagents can achieve higher sensitivity and greater assay reliability.
