An economical and scalable benchtop instrument bringing multiplex protein assays to individual laboratories or centralized core facilities
The Olink original offering: 96-plex on the Fluidigm Biomark
Olink started its commercial laboratory in the Boston area in 2016, based upon the Proximity Extension Assay technology and method published in a 2014 PLoS One paper entitled “Homogenous 96-plex PEA immunoassay exhibiting high sensitivity, specificity, and excellent scalability”. One interesting aspect of this technology (and subsequent iterations) is how the 96-well plate format and the setup of both internal controls and sample- and plate-controls have stayed the same over the years. The 96-plex assays have since expanded to a total of 15 different Target 96 panels (14 human panels, one mouse) each with a disease focus. (The list of available panels can be found here.)
The advantages of the technology are many-fold: with dual-antibody recognition, cross-reactivity of antibodies are minimized, yielding high specificity; by utilizing complementary DNA barcode tags with extension and PCR very small volumes of biofluids are required; and the technology for multiplexing has scaled up to 384, 1,500 (and soon double that to 3,000) protein biomarkers. (It is important to note however that the higher plex 384 and up are read out via Next Generation Sequencing (NGS) instead of real-time PCR as with the Signature Q100 instrument.)
Olink has an advantage of knowing the precise identity of the protein biomarker to be measured. Alternative methods of protein measurement in plasma, such as SomaLogic’s SOMAmers (modified oligonucleobases in-vitro selected to have specific binding kinetics) or Seer’s multi-nanoparticle protein coronas read out on mass spectroscopy, rely on complex software-dependent deconvolution to verify the identity of the protein being measured. There are additional protein analysis technology platforms on the horizon whose details are still undisclosed such as Nautilus; protein sequencing efforts such as Encodia and Quantum-Si are also in the offing.
One important nuance of protein analysis (as compared to, say DNA analysis) is the relative abundance of the proteins to be measured. In both unfractionated and immunodepleted plasma, only 50 proteins account for a full 90% of the proteins measured. (Here’s a reference for you, that has ‘limitations of plasma proteomics’ in its title.) Measuring accurately the long tail of dozens to thousands of proteins from a plasma sample is no mean feat.
The DNA technology used for reading out the abundance of the protein targets (92 markers from each of 96 samples) was a microfluidic real-time PCR system from Fluidigm called the BioMark. Two barriers of adoption for this instrument were its relatively high cost, as well as its large size: 30 inches square, it weighs over 300 pounds (140 kg). Today, Olink announces a new instrument to replace the BioMark for proteomic measurements, called the Olink Signature Q100.
A new generation of instrumentation and more assays to come
The new Olink Signature Q100 is a fraction of the cost, and a fraction of the size, of the BioMark it replaces. The consumable chip, which Fluidigm calls the Integrated Fluidic Circuit (IFC), has not changed at all for the new Signature Q100; in addition, a separate IFC controller instrument needed for the BioMark has now been integrated into the Signature Q100. The processing time remains the same for both instruments (about two hours in total for the DNA readout, however this does not include the time for performing the PEA assay).
The Signature Q100 is only for Olink assays, not for routine real-time PCR applications, in case you were wondering.
The Target 48 Cytokine Panel along with the aforementioned fifteen Target 96 panels will be able to be run on the Signature Q100. One important difference between the Target 48 and the Target 96 is the measurement units; the Target 48 has internal calibrators in order to output absolute quantitation, in mass per volume (pg / mL or ng / mL) units. The Target 96 has a Normalized Protein eXpression (NPX) relative value, measured in log2 units. Thus for legacy datasets that require absolute quantitation, the Target 48 is what you want. For new projects, the wide scope of the existing Target 96 panels points you to the Target 96 lineup.
In addition, Olink offers the option to build Focus Panels, a custom offering of up to 21 protein markers. And the Signature Q100 will run all three offerings, from 21 to 92 targets.
It is expected that additional Target 48 panels will be offered in the future, although these have not been announced yet.
A new offering in a competitive market
The existing market for 10 to 50 biomarkers is held by Luminex and MesoScale Discovery. Luminex customers tell us that there is wider variability with Luminex assays, so much so that scientists will typically run samples in duplicate or triplicate to get more reliable results. Recently the acquisition of Luminex was announced by the Italian diagnostic company DiaSorin. MesoScale customers appreciate the data quality but are hampered by its limited multiplexing capability.
Olink’s Target 48 and Target 96 running on the Signature Q100 offer higher multiplex and no compromise of the data quality, all at an affordable price. Per Dr. Leo Joosten of the Radboud University Medical Center in Nijmegen The Netherlands:
The Signature system gives us more flexibility and will reduce the average cost per sample, which will allow projects with lower budgets to also profit from the Olink technology. We see the Olink Signature system as a perfect addition to our current in-house protein analysis capabilities. One of the other key advantages of the Olink platform is that it uses very small sample volumes.Dr. Leo Joosten, Prof of Mechanisms of Inflammatory Disease at the Radboud University Medical Center in Nijmegen The Netherlands
On June 8, 2021 Olink will be presenting a webinar about the new instrument along with data comparing the Target 48 product against current equivalent offerings from Luminex and MesoScale Discovery. Called “Announcing Olink’s Target 48: A New Multiplex Protein Analysis Approach”, you can register for this webinar here. If you’d like to learn more about the Signature Q100 instrument, the product page is here.