A rapid-format isotyping kit makes use of gold-sol-based assay procedures to reduce traditional ELISA kit labor from a day-and-a-half to twenty minutes
An important question is: How do gold-sol-based assay results compare with a traditional ELISA assay. There are a number of ELISA-based isotyping kits on the market. These kits require the customer to supply their own plates, do the coating, incubation and kit development. One latex-bead-based isotyping kit is also marketed, but the sensitivity increase of a gold-sol-based assay versus a latex-based assay gives the advantage to the gold assay.
A study compared monoclonal isotyping results between a commercially available ELISA isotyping kit and the BioAssay Works' rapid-format kit product, Iso-Gold™. The results demonstrated outstanding correlation between these two assay formats. The ELISA kit required controls, the ELISA plate, substrate, and took eight hours of hands-on technician time to coat the plates, block and subsequently perform the assay on twelve different antibodies. The BioAssay Works’ Iso-Gold product produced ELISA-like results in five minutes (twenty minutes including labor). See the image below.
The Iso-Gold™ kit pipetting time was ten minutes and all twenty assays were run simultaneously. Each was read at five minutes. Thus the total hands-on time, including scoring of the results, was under twenty minutes. In addition to the correct interpretation of the Isotype result, the level of contaminating antibody in each monoclonal can be accurately determined using the Iso-Gold™ Rapid Mouse-Monoclonal Isotyping Kit. Impurities in the form of contaminating isotypes and subclasses correlate well with the ELISA. Thus the rapid test has the added feature of determining the purity of the monoclonal being tested. See the data table below:
See the test strips below:
Advantages of the gold-sol-based rapid isotyping kit:
- Speed: Five minutes from monoclonal sample onto test strip to results
- Accuracy: Results correlate precisely to ELISA, results validated against standardized controls,
- Efficiency: An improvement of labor efficiency from one day to a few minutes
- Reduction of Waste: If researchers are only interested in monitoring one or just a few monoclonal antibodies, they can perform the tests needed with a single pouch of test strips - using only what is needed,
- Cost: On a price-per-test in comparison to the cost-per-well in ELISA, the Iso-Gold is more expensive. However, when the cost of technician time, laboratory reagents, ELISA substrate (which is often not supplied), access to ELISA reader and unused ELISA test wells, the cost of the Iso-Gold kit is competitive.
- Ease of Use: With the ELISA based isotyping kits, in addition to the plate set-up as detailed above, a plate washer is also required, and the lab must have access to a plate reader and printer for interpretation of the data. With the BioAssay Works' Iso-Gold kit, researchers open one pouch containing two cassette strips, put 105 ul of sample from either the monoclonal antibody cell culture supernatant or the ascites into the sample hole of the test strip and the the results are visually read in five minutes. It does not get any easier,
- Kappa and Lambda Identification: BioAssay Works also offers the Iso-Gold kit product in two formats, those with, and those without Kappa and Lambda identification. Some researchers need the Kappa and Lambda option, if nothing else as a validation of the monoclonal.
- Purity: Labs are often required to check their purchased monoclonal antibodies for purity and other characteristics. The purity stated on the label is not always the purity that is in fact in the vial. The Iso-Gold kit quickly delivers the information needed about the antibody.
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The photo above shows three assays detecting E coli 0157. The detection is from a low of 10-3rd to 10-5th power. Here we see an example of ELISA-sensitivity from a rapid format assay.
Procedures for using the Iso-Gold™ kit can be viewed at http://bioassayworks.com/isogold.html.
[See additional product image below]
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