Invitrogen™ NA-XTD™ Influenza Neuraminidase Assay Kit

The NA-XTD kit includes detection reagents and microplates, eliminating the need for luminometers equipped with a reagent injector, and improving ease-of-use. This kit also includes complete assay protocols for quantitating sensitivity to neuraminidase inhibitors in various influenza virus isolates including: human influenza types A and B, A/H1N1 pandemic, avian, equine and porcine viruses.

• Superior performance - improved, long-lived light emission kinetics and read-time flexibility
• High sensitivity - high assay signal-to-noise, detection of low-virus concentrations, and wide assay dynamic range
• Simple instrumentation requirement - no reagent injectors or luminometer needed
• Multiple applications - neuraminidase inhibitor IC50 assays and cell-based virus quantitation

Long-Lived Light Emission Kinetics and Read-Time Flexibility
The NA-XTD assay yields much longer-lived light emission kinetics than does the NA-Star assay, eliminating the need for luminometer instrumentation with reagent injectors and enabling read-time flexibility and batch-mode processing of assay plates. NA-XTD assay signal half-life is approximately 2 hours, longer than the 5-10 minute half-life of the NA-Star assay signal. IC-50 values determined from data collected immediately or up to 3 hours following addition of NA-XTD Accelerator solution are identical.

High Sensitivity
The NA-XTD chemiluminescent assay provides higher detection sensitivity (better low-end detection limit), higher assay signal-to-noise ratio, and wider assay dynamic range than fluorescent assays with the MUNANA substrate. The NA-XTD assay also typically demonstrates slightly higher signal-to-noise than the NA-Star assay. The NA-XTD assay provides 2 to 50-fold higher sensitivity by signal-to-noise ratio than MUNANA-based fluorescence assays, depending on the virus isolate. The NA-XTD assay provides a dynamic range of detection of 3 to 4 orders of magnitude of neuraminidase enzyme concentration, compared to 2 to 3 orders of magnitude range with fluorescent MUNANA assays. The wide chemiluminescent neuraminidase assay range enables determination of IC-50 values over a wide range of virus concentrations, eliminating the need to titer virus prior to performing IC50 determination assays.

Simple Instrumentation Requirement
Optimally, a small sample of culture media is removed and assayed directly with NA-XTD reagents, permitting multiple samples to be assayed over time.

Specifications

• Detection Method: Chemiluminescent
• For Use With Equipment: Luminometer (Microplate)
• Form: Liquid
• Format: 96-well plate
• High Throughput Compatibility: High Throughput-Compatible
• Readout: End Point
• Substrate: NA-XTD
• Substrate Properties: Chemical Substrate
• Substrate Type: Neuraminidase Substrate
• Target Enzyme: Neuraminidase, Sialidase