Human Cystatin C Quantikine ELISA Kit Summary

Product Summary

The Quantikine Human Cystatin C Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human Cystatin C in cell culture supernates, serum, plasma, saliva, urine, and human milk. It contains NS0-expressed recombinant human Cystatin C and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human Cystatin C 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 naturally occurring human Cystatin C.

Preparation and Storage

Background: Cystatin C

Cystatin C is a secreted cysteine protease inhibitor that inhibits Cathepsins B, H, K, L, and S. Cystatin C serum concentration correlates closely to the glomerular filtration rate (GFR); elevated levels are associated with coronary artery and cardiovascular disease risk. Dysregulation of Cystatin C can modulate tumor growth and metastasis. In humans, the L68Q variant forms dimers and oligomers more easily than wild type protein and is the cause for hereditary Cystatin C amyloid angiopathy.

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.