Traditional enzyme-linked immunosorbent assays (ELISAs) are often used to detect and quantify the levels of an analyte from a range of complex sample matrices (e.g. human serum, urine, or blood) where an abundance of other proteins and molecules are present. While compatible with complex matrices, a colorimetric ELISA is susceptible to the constraint of a narrow linear range for the optical density (OD), which is common to absorbance-based measurements. The smaller dynamic range (~ 2 logs) of the assay decreases the likelihood that your unknown sample concentration will fall within the standard curve and introduces the challenge of testing multiple dilutions from the same, potentially limited, sample. Repeat dilution testing of the same sample also requires additional assay wells and often leads to purchasing additional kits or coating additional assay plates to accurately quantify all your samples. Chemiluminescent ELISAs can be more sensitive, but require vast amounts of antibody, increasing the cost of the assay, and lack signal stability due to the nature of the rapid decline in luminescence over time.
Similarly, western blotting is widely used as a semi-quantitative method to determine and compare amounts of protein. These assays can suffer from limited sensitivity and throughput. Because western blotting involves a multistep protocol, variation and errors can occur at any step, reducing the reliability and reproducibility of results.
PerkinElmer offers a range of immunoassay technologies that enable selection of the optimal immunoassay platform for your requirements. From sample compatibility to sample volume, throughput, detectable range, signal window, signal stability, reproducibility, automation compatibility, and desired speed of results, PerkinElmer offers immunoassay technology platforms, pre-configured kits, and customizable reagents for superior results.
DELFIA® TRF is a proven, robust wash-based immunodetection platform with over 20 years of history. DELFIA has a similar assay principle and workflow to that of a traditional ELISA, but with the added benefits of a stable, time-resolved fluorescent signal improved assay dynamic range. DELFIA also offers the ability for multiplexing. DELFIA TRF is compatible with the widest range of sample types, ranging from simple buffers, cell supernatants, and cell lysates to complex biological samples, including tissue, serum, plasma, and blood.
Below is are the workflows for a DELFIA TRF assay and a traditional ELISA.
LANCE® TR-FRET is a no-wash proximity assay technology that combines the benefits of time resolution (TR) with fluorescence resonance energy transfer (FRET) principles by using energy donor and energy acceptor fluorophore labels. It’s everything you love about TRF detection with fastest results and no wash steps. LANCE TR-FRET is compatible with buffer, cellular supernatant and cell lysate samples.
Below is a workflow comparison between a LANCE TR-FRET assay and a traditional ELISA.
Alpha is a bead-based, no-wash luminescent technology. When Alpha Donor and Acceptor beads are brought together through binding to target, a cascade of chemical reactions is set in motion, creating an amplified signal. These versatile beads are conjugated with various biomolecules that enable detection of unique biological events, offering maximum flexibility. Alpha technology is compatible with a wide range of sample types ranging from simple buffers, cell supernatants, and cell lysates to complex tissue, serum, plasma, and other biological samples.
Alpha offers the benefits over ELISAs including:
Below is a workflow comparison between an Alpha assay and a traditional ELISA.