Introduction
Single-molecule Array (Simoa) technology enables ultra-high sensitivity detection of proteins in body fluids such as serum and plasma, mainly in the direction of oncology, neurology, infectious diseases, immune inflammation, reproduction, ophthalmology, cardiovascular and pharmaceuticals.
The sensitivity of ELISA can generally only reach the pg/mL level, which is often inadequate for the detection of ultra-low-abundance proteins. However, accurate detection of ultra-low-abundance proteins is of great significance for disease mechanism research and prediction of disease occurrence and regression. Along with the development of health industry and precision medicine, the contradiction between the technical bottleneck of traditional methods and the huge market demand is becoming more and more obvious. Simoa technology can solve this problem. The technology is 1000 times more sensitive than ELISA. It brings protein detection technology directly into the era of single molecule, digital detection, and becomes the dominant technology in the field of fg-level ultra-low-abundance protein detection.
Creative Proteomics offers Simoa cytokine and protein assay services. We can achieve:
- Detection of ultra-low abundance neurofactors such as NfL, Tau, pTau, Aβ40, Aβ42 in serum/plasma
- Detection of inflammatory factors in trace samples such as atrial fluid, vitreous humor, and tears
- Protein quantification of single cells, enabling protein detection in single embryonic cell culture supernatant
- Detection of PD1, PD-L1 and other proteins in rare sample types such as exosomes
Advantages of Simoa Assay
- High sensitivity: sensitivity up to single-molecule level fg/mL for detection of very low concentrations of protein markers, providing a powerful tool for detection and validation of new biomarkers. Low sample content required for the test, saving precious samples and reducing matrix effects.
- Fully automated: Simoa HD-X analyzer automates dilution, mixing, washing, incubation and result readout/analysis, enabling one-stop detection from sample to result, ensuring reproducible and accurate results.
- Multiplex detection: Up to 10 different target molecules can be accomplished simultaneously within the same chip, allowing simultaneous detection of multiple indicators in one sample, reducing the amount of samples and actual usage and saving costs.
- High precision: Digital and automated technologies enable experimental results with coefficients of variation (CVs) of less than 10%, resulting in scientifically reliable results.
- Wide linearity range: digital detection and analog detection are used to analyze data for low and high concentration samples, respectively. The dynamic range of the assay is >4 orders of magnitude.
Principle of Simoa Analysis Technology
The biological principle of the Simoa assay remains the same as that of the double antibody sandwich ELISA. The Simoa technology differs in that approximately 250,000 capture antibodies are encapsulated on small 2.7 μm magnetic beads. Biotin-labeled detection antibodies and affinity-coupled enzymes and substrates are added to the assay. The individual beads are individually enclosed in 238,000 4.5 μm reaction wells by a layer of oil. Since the reaction system is only 50 femtoliters per well, which is 2 billion times smaller than a conventional ELISA, the catalytic substrate can generate 3,000 fluorescent molecules even if only one molecule is present in the well. The signal can be captured by the CCD camera, and the Poisson distribution theory can be used to calculate the protein concentration value corresponding to the positive fluorescent wells (On Well), realizing the desire of digital single molecule detection.
SiMoA schematic workflow showing stepwise procedures performed to quantify cytokines in single cells (Saxena et al., 2018).
Sample Requirements
Samples from humans, mice, rats, primates, pigs, horses, dogs, cats and other species.
Samples can be tested: serum, plasma, cerebrospinal fluid, cell culture supernatant, exosomes, atrial fluid, vitreous humor, tears, sweat, urine, saliva, microscopic cells, individual blastocyst cultures, blood topographies, clots, etc.
Creative Proteomics can provide you with a one-stop solution for cytokine and protein detection and quantification through single molecule array technology. Please contact us if you would like to employ other assay technologies or inquire about this service. We look forward to working with you.
Reference:
- Saxena, A., Dagur, P. K., et al (2018). Ultrasensitive Quantification of cytokine proteins in single lymphocytes from human blood following ex-vivo stimulation. Frontiers in immunology, 9, 2462.
