DESCRIPTION

Securin, also known as PTTG1, is a 22 kDa protein crucial for maintaining genomic stability by preventing premature sister chromatid separation during mitosis. It is a proto-oncogene first identified in rat pituitary tumor cells and is overexpressed in various cancers, including those of the pituitary gland, kidney, and colorectal cancer. Securin plays a key role in cell cycle progression and is involved in tumorigenesis, metastasis, and resistance to cancer treatments. Additionally, Securin interacts with p53 and modulates its transcriptional activity. Its expression is associated with poor prognosis in multiple malignancies and may serve as a potential biomarker for cancer diagnosis and treatment.

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 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	10.24	0.62	6.06
2	8	2.64	0.15	5.74
3	8	1.52	0.04	2.44

Inter-assay Precision

Sample	n	Mean (ng/mL)	SD	CV%
1	16	9.57	1.11	11.56
2	16	2.59	0.12	4.79
3	16	1.52	0.05	2.98

RECOVERY

The recovery of human Securin spiked to three different levels throughout the range of the assay in cell lysate was evaluated.

Sample Type		Average% of Expected	Range (%)
Cell lysate	1:32	84	79-88

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 cell lysate was initially diluted 1:4.)

		Cell lysate
1:2	Average% of Expected	100
	Range (%)	-
1:4	Average% of Expected	107
	Range (%)	104-109
1:8	Average% of Expected	96
	Range (%)	88-103
1:16	Average% of Expected	87
	Range (%)	79-94

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human Securin Sandwich ELISA Kit produced at Sunlong Medical™.