Product Name:	Human CD4(T-cell surface glycoprotein CD4) ELISA Kit
Product Code:	HUFI03238
Size:	96 Assays
Alias:	CD4, CD4 antigen, CD4 antigen, p55, CD4 molecule, CD4 receptor, CD4mut, T-cell surface antigen T4, Leu-3, T-cell surface glycoprotein CD4
Detection method:	Sandwich ELISA, Double Antibody
Application:	This immunoassay kit allows for the in vitro quantitative determination of Human CD4 concentrations in serum plasma and other biological fluids.
Sensitivity:	37.5pg/ml
Range:	62.5-4000pg/ml
Storage:	4°C for 6 months
Note:	For Research Use Only

Recovery:	Matrices listed below were spiked with certain level of Human CD4 and the recovery rates were calculated by comparing the measured value to the expected amount of Human CD4 in samples. Enquire for more information.
Linearity:	The linearity of the kit was assayed by testing samples spiked with appropriate concentration of Human CD4 and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected. Enquire for more information.
CV(%):	Intra-Assay: CV<8% Inter-Assay: CV<10%

Component	Quantity	Storage
ELISA Microplate (Dismountable)	8×12 strips	4°C for 6 months
Lyophilized Standard	2	4°C/-20°C
Sample/Standard Dilution Buffer	20ml	4°C
Biotin-labeled Antibody(Concentrated)	120ul	4°C (Protect from light)
Antibody Dilution Buffer	10ml	4°C
HRP-Streptavidin Conjugate(SABC)	120ul	4°C (Protect from light)
SABC Dilution Buffer	10ml	4°C
TMB Substrate	10ml	4°C (Protect from light)
Stop Solution	10ml	4°C
Wash Buffer(25X)	30ml	4°C
Plate Sealer	5	-

Other materials and equipment required:

Microplate reader with 450 nm wavelength filter
Multichannel Pipette, Pipette, microcentrifuge tubes and disposable pipette tips
Incubator
Deionized or distilled water
Absorbent paper
Buffer resevoir

Uniprot

P01730

UniProt Protein Function:	CD4: Accessory protein for MHC class-II antigen/T-cell receptor interaction. May regulate T-cell activation. Induces the aggregation of lipid rafts. Associates with LCK. Binds to HIV-1 gp120 and to P4HB/PDI and upon HIV-1 binding to the cell membrane, is part of P4HB/PDI- CD4-CXCR4-gp120 complex. Interacts with HIV-1 Envelope polyprotein gp160 and protein Vpu. Interacts with Human Herpes virus 7 capsid proteins. Interacts with PTK2/FAK1; this interaction requires the presence of HIV-1 gp120.
UniProt Protein Details:	Protein type:Membrane protein, integral; Cell surface Chromosomal Location of Human Ortholog: 12p13.31 Cellular Component: T cell receptor complex; endoplasmic reticulum membrane; endoplasmic reticulum lumen; early endosome; plasma membrane; integral to membrane; external side of plasma membrane; lipid raft Molecular Function:protein binding; enzyme binding; transmembrane receptor activity; protein homodimerization activity; zinc ion binding; extracellular matrix structural constituent; coreceptor activity; receptor activity; glycoprotein binding; protein kinase binding; MHC class II protein binding Biological Process: maintenance of cellular protein localization; viral reproduction; positive regulation of interleukin-2 biosynthetic process; cytokine production; T cell selection; positive regulation of calcium-mediated signaling; defense response to Gram-negative bacterium; signal transduction; induction by virus of cell-cell fusion in host; T cell receptor signaling pathway; enzyme linked receptor protein signaling pathway; regulation of defense response to virus by virus; positive regulation of peptidyl-tyrosine phosphorylation; cell surface receptor linked signal transduction; positive regulation of protein kinase activity; T cell costimulation; protein palmitoleylation; innate immune response; entry into host cell; immune response; transmembrane receptor protein tyrosine kinase signaling pathway; T cell differentiation; regulation of T cell activation Disease: Okt4 Epitope Deficiency
NCBI Summary:	This gene encodes a membrane glycoprotein of T lymphocytes that interacts with major histocompatibility complex class II antigenes and is also a receptor for the human immunodeficiency virus. This gene is expressed not only in T lymphocytes, but also in B cells, macrophages, and granulocytes. It is also expressed in specific regions of the brain. The protein functions to initiate or augment the early phase of T-cell activation, and may function as an important mediator of indirect neuronal damage in infectious and immune-mediated diseases of the central nervous system. Multiple alternatively spliced transcript variants encoding different isoforms have been identified in this gene. [provided by RefSeq, Aug 2010]
UniProt Code:	P01730
NCBI GenInfo Identifier:	116013
NCBI Gene ID:	920
NCBI Accession:	P01730.1
UniProt Secondary Accession:	P01730,Q4ZGK2, Q5U066, Q9UDE5, B2R737, D3DUS5,
UniProt Related Accession:	P01730
Molecular Weight:	458
NCBI Full Name:	T-cell surface glycoprotein CD4
NCBI Synonym Full Names:	CD4 molecule
NCBI Official Symbol:	CD4
NCBI Official Synonym Symbols:	CD4mut
NCBI Protein Information:	T-cell surface glycoprotein CD4; CD4 receptor; CD4 antigen (p55); T-cell surface antigen T4/Leu-3
UniProt Protein Name:	T-cell surface glycoprotein CD4
UniProt Synonym Protein Names:	T-cell surface antigen T4/Leu-3; CD_antigen: CD4
Protein Family:	CD40 ligand
UniProt Gene Name:	CD4
UniProt Entry Name:	CD4_HUMAN

*Note: Protocols are specific to each batch/lot. For the correct instructions please follow the protocol included in your kit.

Before adding to wells, equilibrate the SABC working solution and TMB substrate for at least 30 min at 37°C. When diluting samples and reagents, they must be mixed completely and evenly. It is recommended to plot a standard curve for each test.

Step	Protocol
1.	Set standard, test sample and control (zero) wells on the pre-coated plate respectively, and then, record their positions. It is recommended to measure each standard and sample in duplicate. Wash plate 2 times before adding standard, sample and control (zero) wells!
2.	Aliquot 0.1ml standard solutions into the standard wells.
3.	Add 0.1 ml of Sample / Standard dilution buffer into the control (zero) well.
4.	Add 0.1 ml of properly diluted sample ( Human serum, plasma, tissue homogenates and other biological fluids.) into test sample wells.
5.	Seal the plate with a cover and incubate at 37 °C for 90 min.
6.	Remove the cover and discard the plate content, clap the plate on the absorbent filter papers or other absorbent material. Do NOT let the wells completely dry at any time. Wash plate X2.
7.	Add 0.1 ml of Biotin- detection antibody working solution into the above wells (standard, test sample & zero wells). Add the solution at the bottom of each well without touching the side wall.
8.	Seal the plate with a cover and incubate at 37°C for 60 min.
9.	Remove the cover, and wash plate 3 times with Wash buffer. Let wash buffer rest in wells for 1 min between each wash.
10.	Add 0.1 ml of SABC working solution into each well, cover the plate and incubate at 37°C for 30 min.
11.	Remove the cover and wash plate 5 times with Wash buffer, and each time let the wash buffer stay in the wells for 1-2 min.
12.	Add 90 µl of TMB substrate into each well, cover the plate and incubate at 37°C in dark within 10-20 min. (Note: This incubation time is for reference use only, the optimal time should be determined by end user.) And the shades of blue can be seen in the first 3-4 wells (with most concentrated standard solutions), the other wells show no obvious color.
13.	Add 50 µl of Stop solution into each well and mix thoroughly. The color changes into yellow immediately.
14.	Read the O.D. absorbance at 450 nm in a microplate reader immediately after adding the stop solution.

When carrying out an ELISA assay it is important to prepare your samples in order to achieve the best possible results. Below we have a list of procedures for the preparation of samples for different sample types.

Sample Type	Protocol
Serum	If using serum separator tubes, allow samples to clot for 30 minutes at room temperature. Centrifuge for 10 minutes at 1,000x g. Collect the serum fraction and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles. If serum separator tubes are not being used, allow samples to clot overnight at 2-8°C. Centrifuge for 10 minutes at 1,000x g. Remove serum and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles.
Plasma	Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples at 4°C for 15 mins at 1000 × g within 30 mins of collection. Collect the plasma fraction and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles. Note: Over haemolysed samples are not suitable for use with this kit.
Urine & Cerebrospinal Fluid	Collect the urine (mid-stream) in a sterile container, centrifuge for 20 mins at 2000-3000 rpm. Remove supernatant and assay immediately. If any precipitation is detected, repeat the centrifugation step. A similar protocol can be used for cerebrospinal fluid.
Cell culture supernatant	Collect the cell culture media by pipette, followed by centrifugation at 4°C for 20 mins at 1500 rpm. Collect the clear supernatant and assay immediately.
Cell lysates	Solubilize cells in lysis buffer and allow to sit on ice for 30 minutes. Centrifuge tubes at 14,000 x g for 5 minutes to remove insoluble material. Aliquot the supernatant into a new tube and discard the remaining whole cell extract. Quantify total protein concentration using a total protein assay. Assay immediately or aliquot and store at ≤ -20 °C.
Tissue homogenates	The preparation of tissue homogenates will vary depending upon tissue type. Rinse tissue with 1X PBS to remove excess blood & homogenize in 20ml of 1X PBS (including protease inhibitors) and store overnight at ≤ -20°C. Two freeze-thaw cycles are required to break the cell membranes. To further disrupt the cell membranes you can sonicate the samples. Centrifuge homogenates for 5 mins at 5000xg. Remove the supernatant and assay immediately or aliquot and store at -20°C or -80°C.
Tissue lysates	Rinse tissue with PBS, cut into 1-2 mm pieces, and homogenize with a tissue homogenizer in PBS. Add an equal volume of RIPA buffer containing protease inhibitors and lyse tissues at room temperature for 30 minutes with gentle agitation. Centrifuge to remove debris. Quantify total protein concentration using a total protein assay. Assay immediately or aliquot and store at ≤ -20 °C.
Breast Milk	Collect milk samples and centrifuge at 10,000 x g for 60 min at 4°C. Aliquot the supernatant and assay. For long term use, store samples at -80°C. Minimize freeze/thaw cycles.