SomaLogic Inflammation Panel I
SomaLogic Inflammation Panel I Composition
The SOMAmer reagents in this panel target the following 16 proteins, all of which participate in inflammatory processes.
Inflammatory conditions are observed in a variety of conditions including cardiovascular diseases, metabolic conditions, infectious diseases, and cancer.
This panel can be used to monitor the level of a number of inflammation-related markers and has not been validated for any particular clinical use, but as an overall screen for inflammation levels.
Cytokines/chemokines are represented by IL-8 and IP-10 (CXCL10), while acute phase proteins are represented by CRP (pentraxin). Matrix metalloproteinases, represented by MMP-1, -7, -8, -9, -12, and -13, effect extracellular matrix proteolysis which is essential to inflammation; they also modulate chemokine activity and gradients, and activate or inactivate cytokines by proteolytic processing. Tissue inhibitors of metalloproteinases (TIMP-1, -2, and -3) help regulate MMPs, usually by binding to MMPs and inactivating them. Circulating MMPs are often bound to TIMPs. Adiponectin, produced primarily by adipocytes, has been found to have multiple anti-inflammatory activities. The cell adhesion molecules sICAM-1 and sE-selectin both play crucial roles in the trafficking of inflammatory cells. VEGF121 is a signaling protein that promotes angiogenesis, an important part of inflammation and wound healing.
Sample Processing Requirements
Recommended blood sample collection protocol
(Please note that serum is the required sample type for this test).
1. Check the expiration date on all of the tubes.
2. Perform the venipuncture per institutional guidelines.
3. Completely fill all tubes. If blood is being drawn for several tests (including serum- and plasma-based), fill the tubes in the following order:
- Citrate plasma;
- Serum: red, gold or tiger-top tubes;
- EDTA plasma: lavender top tubes of Pearl Top PPT plasma tubes.
4. Invert the tubes 8-10 times and place upright in a rack.
General blood sample processing requirements
The proper processing of the collected samples is critical. Samples should be processed and frozen at -80° C within two hours of collection.
- Allow serum to clot for 45 minutes at room temperature prior to centrifugation.
- Centrifuge serum tubes. Spin at 2200 x g (not RPM) for 15 minutes. Observe separation of blood cells and serum, with serum layer on top.
- Draw off only the serum and aliquot into appropriately labeled tubes.
- Aliquot samples immediately and then place aliquoted samples in a -80°C freezer.
Samples are to remain frozen at all times.
Ship samples for overnight delivery on dry ice with a copy of the test requisition (available upon request) in the packaging. Follow all US Department of Transportation and institutional requirements for labeling and packaging for shipping clinical specimens on dry ice.
Samples will be rejected if they arrive in one or more of the following conditions:
- In original sample collection tubes
- With significant hemolysis based on visual observation of a dark red color in the sample
- Inadequate volume
- Samples from a patient known to have SLE
The assay starts with SOMAmer reagents, which are synthesized containing functional domains including a biotin attached to the sequence via a photo-cleavable linker, and a fluorescent Cyanine 3 dye molecule. All of these functional groups are added to 5’ end of the DNA sequence of SOMAmer reagent. Before assay is started, SOMAmer reagents are immobilized onto streptavidin(SA)-coated beads. The patient serum sample dilutions are added to plate that contain different SOMAmer reagent mixes to allow for multiplexed measurement of different protein concentrations in the sample. During the equilibration step, proteins bind to SOMAmer reagents forming protein-SOMAmer complexes. The streptavidin beads are washed to remove all non-bound analytes and non-specifically associated proteins and other matrix constituents. Proteins that remain bound to the SOMAmer reagents are tagged using an NHS-biotin reagent (labeling step). After the labeling reaction, the streptavidin beads are exposed to an anionic competitor solution that prevents non-specific interactions from reforming once the loosely associated non-specific binding material dissociates. The SOMAmer-protein complexes are then released into solution by irradiating the photo-cleavable linker using ultraviolet light at a point, separating the biotin tag from the SOMAmer reagent. The solution containing SOMAmer-protein complexes is collected and the biotinylated proteins are then captured with streptavidin-coated magnetic beads. The beads are washed extensively to remove uncomplexed SOMAmer reagents. Next, SOMAmer reagents in protein-SOMAmer complexes are dissociated from their protein targets, and the eluted SOMAmer reagents are recovered and quantified through hybridization onto DNA microarrays. The Cyanine 3 dye intrinsic to the SOMAmer reagent is detected with the Agilent Microarray scanner. The amount of SOMAmer reagent detected after the hybridization reactions is proportional to the epitope availability of the target protein in the serum sample.