ERFE – FAQs
Erythroferrone (ERFE) Research Use Only (RUO) Assay Information
Yes the Intrinsic LifeSciences ERFE RUO assay is patented in the US. Additional patents are pending in the US and abroad.
Currently the ERFE RUO assay is not FDA approved. However, the assay has been used in a growing number of peer-reviewed studies and is marketed as a Research Use Only (RUO) assay. For recent scientific studies using the Intrinsic Erythroferrone IETM ELISA kit, visit the ERFE publications section under the Technical Information tab. We have performed ERFE RUO analysis for academic, clinical, government and pharmaceutical customers, worldwide.
ERFE is measured in plasma and serum using a patented colorimetric sandwich enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the reporter molecule.
Serum and plasma erythroferrone is stable for up to one year when samples are stored -80°C. Freeze samples as soon as possible after collection. At this point in our understanding of ERFE biology, we recommend storing samples at -80oC or colder. Avoid multiple freeze/thaw cycles. Stability testing updates will be provided as they become available.
We have established the reference range for erythroferrone in first time blood donors here in San Diego using the Intrinsic Erythorferrone IETM RUO ELISA kit.
Reference Range (5-95% CI)
Female: 0.16 – 2.26 ng/ml
Male: 0.16 – 6.32 ng/ml
Sample Collection for ERFE RUO Assay
For serum, collect blood from fasting subjects (preferred) in a red top tube (for example BD #366431). Immediately after blood collection, place the tubes upright in a rack and allow blood to clot at room temperature for a minimum of 2 hours.
For plasma, collect blood from fasting subjects in a tube containing either lithium heparin (green top, for example BD #367884) or EDTA (purple top, for example BD #367861). Invert tubes several times immediately after collection and place horizontally on a platform rocker at moderate speed for 2 hours at room temperature.
To harvest serum or plasma, centrifuge the tubes at 1500xg for 15 minutes and collect supernatant. Transfer 0.25 ml into a clean 0.5 to 2.0 ml cryogenic vial and store frozen at -80oC until shipment.
To minimize sample loss during liquid handling, we prefer externally threaded cryogenic vials (for example USA Scientific Safety-Seal Screw Cap Tubes, cat# 1405-9700 or for example Nalgene System 100 cryoware). If desired, contact us for advice regarding selection of cryogenic vials for your project.
After collection, serum or plasma samples must be stored at -80°C until shipment. Please consult the ERFE stability FAQ for additional information.
The minimum sample volume required for the ERFE assay is 0.25 ml (0.5 ml preferred). This volume is necessary to meet our liquid handling requirements and ensures sufficient volume for sample repeats, if necessary. Smaller sample volumes can be accepted upon request, particularly for infant and pediatric studies. Samples can be returned after testing – contact us to discuss this in more detail.
Samples held at room temperature for 6 or more hours before centrifugation.
Samples that thawed during transport.
Samples that are largely hemolyzed or obtained from frozen whole blood.
Request Erythroferrone (ERFE) Assays
Shipping Information for ERFE RUO Testing
For shipment of biological substances on dry ice, the package must consist of three components: a primary receptacle (e.g. a cardboard cryogenic storage box with divider or similar device), a secondary package that includes absorbent material, and a rigid outer package such as an insulated, leak-proof, thermal shipping container. The sample tubes are placed inside the primary receptacle, the primary receptacle is placed inside the secondary package in such a way that, under normal conditions of transport, they cannot break, be punctured or leak their contents. If leakage does occur during transport, the absorbent material inside the secondary package will contain the spill. The secondary package is placed into the leak-proof shipping container and dry ice is placed around and above the secondary package.
All samples must be shipped on dry ice in an approved leak-proof container, by overnight delivery. Always consult national and international regulations for the safe shipment of biological substances on dry ice. Use sufficient dry ice to allow for a 2 day transit time, in case of a delivery delay. Always ship samples on Monday, Tuesday or Wednesday for overnight delivery. We can receive samples any day from Monday through Friday during regular business hours. We routinely receive international shipments from World Courier and FedEx. Contact your preferred carrier for additional shipment instructions and schedules.
For erythroferrone RUO testing, please call 858-459-1758 or email us firstname.lastname@example.org to confirm that you intend to send samples. Please attach an electronic sample manifest (e.g. in Excel file format) in the email and place a printout of the electronic sample manifest in the shipment to enable us to confirm receipt of the samples that were received.
Ship all properly packed samples to:
505 Coast Boulevard South, Suite 408
La Jolla, CA 92037