DESCRIPTION

SMAD4, also called SMAD family member 4, Mothers against decapentaplegic homolog 4, or DPC4 (Deleted in Pancreatic Cancer-4) is a highly conserved protein present in all metazoans. It belongs to the SMAD family of transcription factor proteins, which act as mediators of TGF-β signal transduction. The TGF-β family of cytokines regulates critical processes during the lifecycle of metazoans, with important roles during embryo development, tissue homeostasis, regeneration, and immune regulation. SMAD4 interacts with R-Smads, such as SMAD2, SMAD3, SMAD1, SMAD5 and SMAD8 (also called SMAD9) to form heterotrimeric complexes. Transcriptional coregulators, such as WWTR1 (TAZ) interact with SMADs to promote their function. Once in the nucleus, the complex of SMAD4 and two R-SMADS binds to DNA and regulates the expression of different genes depending on the cellular context. Smad4 GSK3 phosphorylations have been proposed to regulate the protein stability during pancreatic and colon cancer progression.

PRINCIPLE OF THE ASSAY

Sandwich ELISA structure (Detection antibody labeled with HRP) A capture antibody is pre-coated onto the bottom of wells which binds to analyte of interest. A detection antibody labeled with HRP also binds to the analyte. TMB acts as the HRP substrate and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns 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 20 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 24 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	20	1,231.1	90.0	7.3
2	20	222.3	23.0	10.3
3	20	53.3	3.1	5.8

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	24	1,236.8	82.1	6.6
2	24	240.3	11.4	4.7
3	24	56.1	3.5	6.2

RECOVERY

The recovery of human SMAD4 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human serum	1:2	75	70-79
	1:4	90	77-116
Cell lysate	1:20	111	103-123
	1:40	110	99-126

LINEARITY

To assess the linearity of the assay, human serum samples were spiked with high concentrations of human SMAD4 and diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. Cell lysate samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The cell lysate was initially diluted 1:2.5.)

		Human serum(Sample Diluent PT 3)	Cell lysate(Sample Diluent PT 3-ef)
1:2	Average% of Expected	89	100
	Range (%)	88-90	-
1:4	Average% of Expected	91	92
	Range (%)	74-108	91-93
1:8	Average% of Expected	103	107
	Range (%)	86-120	106-107
1:16	Average% of Expected	93	105
	Range (%)	92-94	98-111

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human SMAD4 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
• Payment: T/T 100% in advance; PayPal; Alibaba Trade Assurance
• Shipping: FedEx / DHL / UPS express; cold-chain packing available on request
• Price: USD, per kit (48T / 96T options available)