THE DIP AND READ™ ELISA ASSAY — CONVERTED ELISA

ELISA has been a common practice in the biology research laboratory since the 1970's. Despite its widespread adoption in industry, its variability in results, susceptibility to human error, labor intensive workflow, and slow times-to-result remain as big hurdles for users looking to adopt ELISA in high throughput applications. Faster times-to-results, better consistency, and less human intervention are the prerequisites for next generation of high-throughput laboratory operation.

The Octet platform, with its industry-leading label-free Dip and Read format and ease-of-use, offers an excellent solution to replace assays currently performed on ELISA. The excellent precision offered by the Octet system reduces the number of replicates per sample. The high sensitivity of instruments such as the Octet RED96 or RED384 offers a wide dynamic range of >5 logs, essentially eliminating the need for dilution of samples.

DIRECT QUANTITATAION

Researchers working in bioprocessing will benefit from the Octet platform's direct measurement of crude samples with no pre-measurement instrument priming or post-measurement instrument clean-up. Combined with a wide range of pre-functionalized biosnesors (e.g., Protein A, Protein G, Protein L, etc.), the Octet system greatly expedites lab workflow and increases overall productivity.

In a quantitation measurement, functionalized biosensors are dipped into wells of a 96- or 384-well microplate containing the samples to be measured (Figure 1). Binding data is collected during the brief dip and final results for 96 samples can be obtained in as little as 15 minutes — compared to more than 4 hours in conventional ELISAs. Figures 2a and 2b illustrate the binding measurement of samples in varying concentrations and the standard curve established to calculate sample concentrations, respectively.

Dip and Read quantitation measurements are performed with no user handling, further enhancing laboratory workflow and data consistency. Additionally, Octet biosensors are made of glass fibers and only the very tip of the fiber is functionalized — dipping into the sample does not alter, destroy, or even dilute the samples in any way, making the samples fully recoverable after measurement and reusable in downstream analysis.

MULTI-STEP QUANTITATION

Taking further advantage of Octet systems' high throughput and automated workflow, users can enhance the sensitivity of their measurements by performing sandwich-like assays on the Octet platform. This can be done by utilizing a detection reagent in the measurement to amplify the binding response. The figures below show custom multi-step ELISA assays that have been converted to Octet assays.

RESIDUAL PROTEIN A DETECTION

The Dip and Read Residual Protein A Detection Kit contains biosensors and all reagents required to quantitate column fractions. The Residual Protein A assay provides the sensitivity and accuracy needed for this critical test along with minimal hands-on time and an easy to use protocol.Protein A binds the Fc region of immunoglobulins, particularly IgGs. For this reason, Protein A is often immobilized onto a solid support and used to purify IgG from crude protein mixtures such as serum or ascites. During the purification process, Protein A can leach from the purification column and co-elute with the IgG. Protein A can cause adverse reactions in patients, therefore detecting and minimizing residual Protein A in products purified using a Protein A, or similar purification column is a critical quality control step in antibody therapeutic development and production.

Key Kit Benefits

• Quantitate Protein A or MabSelect SuRe™
• Sensitive and accurate assay
• Easy-to-use Dip and Read protocol
• Minimal hands-on time

Download ForteBio's Technical Note 18: Dip and Read Residual Protein A Detection Kit

CONTAMINANT HOST CELL PROTEIN DETECTION

Host cell protein detection requires an assay that consistently delivers a broad, linear dynamic range, sensitivity to meet FDA guidelines, and unmatched reproducibility from each experiment. The Octet platform delivers consistency in quantitation unlike any other real-time detection tool available. Octet instruments use Dip and Read biosensors with specific capture antibodies immobilized on their tip surfaces to detect and quantify proteins of interest, including host cell proteins. The unique detection method employed by the Octet system provides the sensitivity, accuracy, and robustness required by this critical biotherapeutic assay.

Key Features

• Fast, 2-hour assay, broad dynamic range, more robust than ELISA HCP assays

For more information on HCP assays: Download Host Cell Protein Assay Development Services Datasheet
Don't see the assay you need? Visit our Custom Services page for information on ForteBio's custom assay development services.