Human Follistatin Quantikine ELISA Kit Summary

Product Summary

The Quantikine Human Follistatin Immunoassay is a 5.5 hour solid-phase ELISA designed to measure human Follistatin (FS288, FS300, and FS315) in follicular fluid, cell culture supernates, serum, and plasma. It contains Sf 21-expressed recombinant human Follistatin and antibodies raised against the recombinant factor. It has been shown to accurately quantitate recombinant human Follistatin. Results obtained using natural Follistatin showed linear curves that were parallel to the standard curves obtained using the Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for natural Follistatin.

Preparation and Storage

Background: Follistatin

Follistatin (FST) is a secreted glycoprotein that binds and neutralizes several TGF-beta superfamily proteins including Activin, BMP-6, BMP-7, and GDF-8/Myostatin. It also binds Angiogenin and regulates hematopoietic stem cell adhesion to Fibronectin. Some Follistatin binding partners will also bind Follistatin-like proteins such as FSL-3. Of three follistatin isoforms, the full-length mature follistatin (FST315) is the most abundant and the sole form in plasma, but has lower binding affinity for both activins and heparins than alternative forms. The acidic tail is missing in the splice variant FST288, which shows highest affinity, and partial in the proteolytically produced FST303, which shows intermediate affinity. Genetic deletion of follistatin in mice, or expression of only the FST288 form, is lethal perinatally due to defects of lung, skin and musculoskeletal system. Expression of only the FST315 isoform allows survival, with defects in vascularization and female fertility.

Assay Procedure

Refer to the product datasheet for the complete assay procedure.

Bring all reagents and samples to room temperature before use. It is recommended that all samples, standards, and controls be assayed in duplicate.

1、Prepare all reagents, standard dilutions, and samples as directed in the product insert.

2、Remove excess microplate strips from the plate frame, return them to the foil pouch containing the desiccant pack, and reseal.

3、Add 50 μL of Assay Diluent to each well.

4、Add 50 μL of Standard, control, or sample to each well. Cover with a plate sealer, and incubate at room temperature for 2 hours.

5、Aspirate each well and wash, repeating the process 4 times for a total of 5 washes.

6、Add 100 μL of Conjugate to each well. Cover with a new plate sealer, and incubate at room temperature for 2 hours.

7、Aspirate and wash 5 times.

8、Add 100 μL Substrate Solution to each well.

9、Add 100 μL of Stop Solution to each well. Read at 450 nm within 30 minutes. Set wavelength correction to 540 nm or 570 nm.