DESCRIPTION

Dipeptidyl peptidase 4 (DPP4, also known as CD26) is a type II transmembrane glycoprotein with enzymatic activity. DPP4 plays a crucial role in immune regulation, T-cell activation, and the regulation of chemokine function. DPP4 also interacts with adenosine deaminase (ADA) and the chemokine receptor CXCR4, influencing immune responses and cell migration. Additionally, circulating soluble DPP4 (sDPP4) is released from adipose tissue and acts as a pro-inflammatory adipokine, linking the expansion of adipose tissue with increased inflammation, insulin resistance, and metabolic syndrome.

PRINCIPLE OF THE ASSAY

An anti-tag antibody is pre-coated onto the bottom of wells. After adding antigen or samples, Tagged-Capture antibody and HRP-conjugated detection antibody, a sandwich complex is formed in the solution. TMB acts as a HRP substrate, and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns the solution yellow. The color intensity is proportional to the quantity of bound protein, which is measurable at 450 nm with the correction wavelength set at 630 nm.

PRECISION

Intra-assay Precision (Precision within an assay) Three samples of known concentration were tested 8 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 16 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (ng/mL)	SD	CV%
1	8	12.50	0.28	2.24
2	8	3.20	0.05	1.56
3	8	1.67	0.03	1.80

Inter-assay Precision

Sample	n	Mean (ng/mL)	SD	CV%
1	16	12.90	0.58	4.50
2	16	3.22	0.06	1.86
3	16	1.69	0.04	2.37

RECOVERY

The recovery of mouse DPP4/CD26 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Mouse serum	1:256	87	72-98
	1:512	98	95-100
Tissue lysate	1:1,024	75	70-79
	1:2,048	82	78-86

LINEARITY

To assess the linearity of the assay, samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The mouse serum was initially diluted 1:32. The tissue lysate was initially diluted 1:128.)

		Mouse serum(Sample Diluent PT 4B1)	Tissue lysate(Sample Diluent PT 3)
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	100	108
	Range (%)	94-105	107-108
1:8	Average% of Expected	94	123
	Range (%)	90-98	121-126
1:16	Average% of Expected	84	116
	Range (%)	82-86	103-128

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Mouse DPP4/CD26 One-Step ELISA Kit produced at Sunlong Medical™.

Ordering & shipping

• Minimum order: 1 kit
• Lead time: varies with order quantity and specifications. Please consult your local distributor or our sales team for confirmation
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• Price: USD, per kit (48T / 96T options available)