Product Name:	Human Pulmonary Surfactant Associated Protein A / SPA ELISA Kit
Product Code:	HUFI02867
Size:	96 Assays
Alias:	SPA, Pulmonary Surfactant Associated Protein A, SFTPA1, COLEC4, PSAP, SFTP1, SFTPA, SFTPA1B, PSP-A, PSPA, SP-A, SP-A1, Collectin-4, 35 kDa pulmonary surfactant-associated protein, Alveolar proteinosis protein
Detection method:	Sandwich ELISA, Double Antibody
Application:	This immunoassay kit allows for the in vitro quantitative determination of Human SPA concentrations in serum plasma and other biological fluids.
Sensitivity:	9.375pg/ml
Range:	15.625-1000pg/ml
Storage:	4°C for 6 months
Note:	For Research Use Only

Recovery:

Matrices listed below were spiked with certain level of Human SPA and the recovery rates were calculated by comparing the measured value to the expected amount of Human SPA in samples.

Matrix	Recovery range(%)	Average(%)
serum(n=5)	86-100	92
EDTA plasma(n=5)	85-104	97
UFH plasma(n=5)	86-99	94

Linearity:

The linearity of the kit was assayed by testing samples spiked with appropriate concentration of Human SPA and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected.

Sample	1:2	1:4	1:8
serum(n=5)	92-105%	85-100%	88-105%
EDTA plasma(n=5)	82-99%	82-100%	83-95%
UFH plasma(n=5)	85-92%	87-95%	81-97%

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

Q8IWL2

UniProt Protein Function:	SFTPA1B: In presence of calcium ions, it binds to surfactant phospholipids and contributes to lower the surface tension at the air-liquid interface in the alveoli of the mammalian lung and is essential for normal respiration. Genetic variations in SFTPA1 are a cause of susceptibility to pulmonary fibrosis idiopathic (IPF). Pulmonary fibrosis is a lung disease characterized by shortness of breath, radiographically evident diffuse pulmonary infiltrates, and varying degrees of inflammation and fibrosis on biopsy. It results in acute lung injury with subsequent scarring and endstage lung disease. Genetic variations in SFTPA1 are a cause of susceptibility to respiratory distress syndrome in premature infants (RDS); also known as RDS in prematurity. RDS is a lung disease affecting usually premature newborn infants. It is characterized by deficient gas exchange, diffuse atelectasis, high-permeability lung edema and fibrin-rich alveolar deposits called 'hyaline membranes'. The association between SFTPA1 alleles and respiratory distress syndrome in premature infants is dependent on a variation Ile to Thr at position 131 in SFTPB. Belongs to the SFTPA family.
UniProt Protein Details:	Protein type:Secreted; Secreted, signal peptide Chromosomal Location of Human Ortholog: 10q22.3 Cellular Component: extracellular space; proteinaceous extracellular matrix; collagen; extracellular region Molecular Function:lipid transporter activity; carbohydrate binding Biological Process: respiratory gaseous exchange; lipid transport Disease: Pulmonary Fibrosis, Idiopathic
NCBI Summary:	This gene encodes a lung surfactant protein that is a member of a subfamily of C-type lectins called collectins. The encoded protein binds specific carbohydrate moieties found on lipids and on the surface of microorganisms. This protein plays an essential role in surfactant homeostasis and in the defense against respiratory pathogens. Mutations in this gene are associated with idiopathic pulmonary fibrosis. Alternate splicing results in multiple transcript variants. [provided by RefSeq, May 2010]
UniProt Code:	Q8IWL2
NCBI GenInfo Identifier:	60416440
NCBI Gene ID:	653509
NCBI Accession:	Q8IWL2.2
UniProt Secondary Accession:	Q8IWL2,P07714, Q14DV4, Q5RIR5, Q5RIR7, A8K3T8, B7ZW50 E3VLD8, E3VLD9, E3VLE0, E3VLE1, G5E9J3,
UniProt Related Accession:	Q8IWL2
Molecular Weight:	27,736 Da
NCBI Full Name:	Pulmonary surfactant-associated protein A1
NCBI Synonym Full Names:	surfactant protein A1
NCBI Official Symbol:	SFTPA1
NCBI Official Synonym Symbols:	SPA; PSAP; PSPA; SP-A; SPA1; PSP-A; SFTP1; SP-A1; COLEC4; SFTPA1B
NCBI Protein Information:	pulmonary surfactant-associated protein A1; collectin-4; surfactant protein A1B; alveolar proteinosis protein; surfactant protein A1 variant AD' 6A; surfactant protein A1 variant ACD' 6A; surfactant protein A1 variant AD' 6A2; surfactant protein A1 variant AD' 6A3; surfactant protein A1 variant AD' 6A4; surfactant protein A1 variant AB'D' 6A; surfactant protein A1 variant ACD' 6A2; surfactant protein A1 variant ACD' 6A3; surfactant protein A1 variant ACD' 6A4; surfactant protein A1 variant AB'D' 6A2; surfactant protein A1 variant AB'D' 6A3; surfactant protein A1 variant AB'D' 6A4; surfactant, pulmonary-associated protein A1A; surfactant, pulmonary-associated protein A1B; 35 kDa pulmonary surfactant-associated protein
UniProt Protein Name:	Pulmonary surfactant-associated protein A1
UniProt Synonym Protein Names:	35 kDa pulmonary surfactant-associated protein; Alveolar proteinosis protein; Collectin-4
Protein Family:	Pulmonary surfactant-associated protein
UniProt Gene Name:	SFTPA1
UniProt Entry Name:	SFTA1_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.