DESCRIPTION

Synaptophysin (SYP, also known as major synaptic vesicle protein p38) is a 38-kDa integral membrane glycoprotein that regulates synaptic vesicle endocytosis. It is the most abundant synaptic vesicle protein by mass. Synaptophysin is present in neuroendocrine cells and neurons that participate in synaptic transmission. Synaptic proteins including synaptophysin are reduced in brain tissue from patients with Alzheimer's disease. Synaptophysin is a useful marker for the identification of neuroendocrine cells and neoplasms.

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	5.21	0.11	2.11
2	8	1.43	0.04	2.80
3	8	0.73	0.02	2.74

Inter-assay Precision

Sample	n	Mean (ng/mL)	SD	CV%
1	16	5.23	0.13	2.49
2	16	1.44	0.05	3.47
3	16	0.73	0.02	2.74

RECOVERY

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

Sample Type		Average% of Expected	Range (%)
Human plasma	1:4	98	81-107
	1:8	114	111-117
Cell lysate	1:128	92	88-96

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 1:8.)

		Human plasma(Sample Diluent PT 5)	Cell lysate(Sample Diluent PT 3-ef)
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	91	104
	Range (%)	83-99	103-106
1:8	Average% of Expected	81	106
	Range (%)	75-87	98-113
1:16	Average% of Expected	80	108
	Range (%)	72-88	99-117

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Synaptophysin produced at Sunlong Medical™.