DESCRIPTION

CD33 is a type I transmembrane receptor glycoprotein that functions as an immune inhibitory receptor. It is expressed on myeloid cells, including monocytes, macrophages, and microglia, and plays a role in immune regulation and cell adhesion. CD33 is involved in the suppression of immune responses, particularly in the context of Alzheimer's disease, where it inhibits microglial uptake of amyloid beta. Additionally, CD33 is implicated in the regulation of inflammation and immune cell activation.

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 (pg/mL)	SD	CV%
1	8	4,029.9	147.2	3.7
2	8	985.7	35.0	3.5
3	8	498.4	19.8	4.0

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	4,057.1	119.7	2.9
2	16	986.8	42.8	4.3
3	16	506.5	21.6	4.3

RECOVERY

The recovery of human CD33 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human serum	1:16	110	100-125
Cell lysate	1:64	113	108-124
	1:128	108	106-113

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 1:16.)

		Human serum	Cell lysate
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	102	82
	Range (%)	92-113	77-86
1:8	Average% of Expected	97	85
	Range (%)	95-98	81-89
1:16	Average% of Expected	119	92
	Range (%)	102-135	87-97

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human CD33 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)