iLiteTM antibeta - FAQs
1. What type of interferon is used in the kit?
The iLiteTM antibeta kit contains IFNβ 1a as the drug reference standard.
2. Can I detect neutralizing antibodies to other commercially forms of interferon?
The iLiteTM antibeta kit is capable of detecting neutralizing antibodies to all commercial forms of IFN-beta however, precise quantification of NAb activity can only be ascertained if the patient-specific form of drug is used as the reference standard.
3. How many samples can I analyze on a plate?
20 samples can be screened on a plate i.e. to determine if the sample is negative or positive.
Following screening 5 samples can be tested on a plate to determine the NAb titre with titres of 15 -9155 being tested.
4. What type of human cell is used in the kit?
The cell line used as the "reporter cell" has been designated "PIL5" and is derived from the U937 cell line which can be obtained from public sources as ATCC # CRL-1593.2. These cells have been characterized as human pro-monocytic with the constitutive expression of major histocompatibility complex (MHC) Class II antigens on the cell surface; in particular, the human lymphocyte antigen designated HLA-DR.
5. What is the reporter gene?
The reporter gene is firefly luciferase which is under the genetic control mechanism of the Interferon Sensitive Response Element (ISRE) from Interferon Sensitive Gene 15 (ISG15). These genetic components have been inserted "upstream" of a minimal SV40 promoter.
6. What type of luminometer is needed?
Any good instrument that has the capability to read glow luminescence in a 96-well plate format is suitable e.g. Victor TM Light luminometer, PerkinElmer. The luciferase substrate system is not designed for use with the automated reagent injectors integrated into some luminometers.
7. What are the storage requirements?
Minus 80°C. It is critical that the cells are maintained at -80°C prior to use; storage at temperatures above -60°C could be detrimental to the cells.
8. How does this test compare to traditional BioAssay?
* We have performed a Validation Study to demonstrate that the iLiteTM
antibeta kit has a very good correlation with CPE in the determination of NAB titre
* The iLiteTM test had demonstrates good intra- and inter-lot variation in repeatability and reproducibility.
* The iLiteTM test is quicker and easier to use.
* The CPE assay has many inherent day-to-day and operator-to-operator variables that are difficult to control. Our data suggest that iLiteTM antibeta may be a more sensitive and reliable assay.
9. How does a gene reporter assay work?
The interaction of the IFN in the sample with the IFN receptor on the "reporter cell" initiates a cascade of biosynthetic reactions (e.g., phosphorylation of signal proteins) that results in the induction of some 130 IFN sensitive genes. One of the IFN sensitive genes has been replaced with the gene for the enzyme "firefly luciferase".
Hence, in the presence of IFN in the sample, the luciferase enzyme is produced. The amount of luciferase enzyme produced over time is directly proportional to the amount of IFN in the sample. After the required incubation, the cells are broken open, substrates for the enzyme are added and the luminescence is determined.
10. How long does it take to complete a test?
After the kit has been removed from the freezer and thawed, the results can be available in 19 hours.
11. Why is it important to use the test cells within 15 minutes of thawing?
The cells have been grown to a specific point in the growth cycle of the culture and treated to render them "division arrested". Cells that are thawed and allowed to metabolize may lose their IFN receptors and ability to respond to IFN in a way consistent with the performance claims of the iLiteTM test.
12. What support does Neutekbio provide?
The Company provides complete customer service through phone or e-mail contact.
13. What quality systems are employed at Neutekbio?
Neutekbio follows the ISO 13485:2003 quality management system. The primary objective of ISO 13485:2003 is to facilitate harmonized medical device regulatory standards for quality management systems.
14. What is the batch size?
Neutekbio can supply batch sizes of 40 kits.
15. I intend to use the iLiteTM kit to monitor IFN levels in clinical trials I am conducting. What is the batch to batch variability I can expect to see?
In a study carried out with human serum, the coefficient of variation in inter- and intra-lot analyses was approximately 20%.
16. Do I need to reserve kits from one batch for my studies?
No. Our QUALITY MANAGEMENT SYSTEMS guarantees repeatable and reproducible tests. However, we can send a single customer individual batches of 40 kits.