Description
Human Leptin (LEP) ELISA Kit
The Human Leptin (LEP) ELISA Kit is specifically designed for the quantitative measurement of leptin levels in human serum, plasma, and cell culture supernatants. This kit is highly sensitive and specific, providing accurate and reproducible results for a variety of research applications.Leptin is a key hormone involved in regulating energy balance and body weight, playing a crucial role in metabolism and appetite control.
Dysregulation of leptin levels has been linked to obesity, diabetes, and other metabolic disorders, making it a valuable biomarker for studying these conditions and developing new treatments.With its reliable performance and broad applicability, the Human Leptin (LEP) ELISA Kit is an essential tool for researchers studying leptin and its role in metabolism, obesity, and related health conditions.
| Product Name: | Human Leptin (LEP) ELISA Kit |
| SKU: | HUEB0125 |
| Size: | 96T |
| Target: | Human Leptin (LEP) |
| Synonyms: | Obese protein, Obesity factor, OB, OBS |
| Assay Type: | Sandwich |
| Detection Method: | ELISA |
| Reactivity: | Human |
| Detection Range: | 0.625-40ng/mL |
| Sensitivity: | 0.26ng/mL |
| Intra CV: | 6.2% | ||||||||||||||||||||
| Inter CV: | 9.5% | ||||||||||||||||||||
| Linearity: |
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| Recovery: |
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| Function: | Key player in the regulation of energy balance and body weight control. Once released into the circulation, has central and peripheral effects by binding LEPR, found in many tissues, which results in the activation of several major signaling pathways (PubMed:17344214, PubMed:15899045, PubMed:19688109). In the hypothalamus, acts as an appetite-regulating factor that induces a decrease in food intake and an increase in energy consumption by inducing anorexinogenic factors and suppressing orexigenic neuropeptides, also regulates bone mass and secretion of hypothalamo-pituitary-adrenal hormones. In the periphery, increases basal metabolism, influences reproductive function, regulates pancreatic beta-cell function and insulin secretion, is pro-angiogenic for endothelial cell and affects innate and adaptive immunity (By similarity) (PubMed:8589726, PubMed:11460888, PubMed:19688109, PubMed:24340098, PubMed:25060689). In the arcuate nucleus of the hypothalamus, activates by depolarization POMC neurons inducing FOS and SOCS3 expression to release anorexigenic peptides and inhibits by hyperpolarization NPY neurons inducing SOCS3 with a consequent reduction on release of orexigenic peptides (By similarity). In addition to its known satiety inducing effect, has a modulatory role in nutrient absorption. In the intestine, reduces glucose absorption by enterocytes by activating PKC and leading to a sequential activation of p38, PI3K and ERK signaling pathways which exerts an inhibitory effect on glucose absorption (PubMed:24340098). Acts as a growth factor on certain tissues, through the activation of different signaling pathways increases expression of genes involved in cell cycle regulation such as CCND1, via JAK2-STAT3 pathway, or VEGFA, via MAPK1/3 and PI3K-AKT1 pathways (By similarity) (PubMed:17344214). May also play an apoptotic role via JAK2-STAT3 pathway and up-regulation of BIRC5 expression (PubMed:18242580). Pro-angiogenic, has mitogenic activity on vascular endothelial cells and plays a role in matrix remodeling by regulating the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) (PubMed:11460888). In innate immunity, modulates the activity and function of neutrophils by increasing chemotaxis and the secretion of oxygen radicals. Increases phagocytosis by macrophages and enhances secretion of pro-inflammatory mediators. Increases cytotoxic ability of NK cells (PubMed:12504075). Plays a pro-inflammatory role, in synergy with IL1B, by inducing NOS2 wich promotes the production of IL6, IL8 and Prostaglandin E2, through a signaling pathway that involves JAK2, PI3K, MAP2K1/MEK1 and MAPK14/p38 (PubMed:15899045, PubMed:19688109). In adaptive immunity, promotes the switch of memory T-cells towards T helper-1 cell immune responses (By similarity). Increases CD4(+)CD25(-) T-cell proliferation and reduces autophagy during TCR (T-cell receptor) stimulation, through MTOR signaling pathway activation and BCL2 up-regulation (PubMed:25060689). |
| Uniprot: | P41159 |
| Sample Type: | Serum, plasma, tissue homogenates, cell culture supernates and other biological fluids |
| Specificity: | Natural and recombinant human Leptin |
| Sub Unit: | Interacts with SIGLEC6. |
| Research Area: | Metabolism |
| Subcellular Location: | Secreted |
| Storage: | Please see kit components below for exact storage details |
| Note: | For research use only |
| UniProt Protein Function: | leptin: May function as part of a signaling pathway that acts to regulate the size of the body fat depot. An increase in the level of LEP may act directly or indirectly on the CNS to inhibit food intake and/or regulate energy expenditure as part of a homeostatic mechanism to maintain constancy of the adipose mass. Defects in LEP may be a cause of obesity (OBESITY). It is a condition characterized by an increase of body weight beyond the limitation of skeletal and physical requirements, as the result of excessive accumulation of body fat. Belongs to the leptin family. |
| UniProt Protein Details: | Protein type:Secreted; Secreted, signal peptide; Hormone; Cell development/differentiation Chromosomal Location of Human Ortholog: 7q31.3 Cellular Component: extracellular space; cytoplasm; extracellular region Molecular Function:peptide hormone receptor binding; growth factor activity; hormone activity Biological Process: circadian rhythm; response to dietary excess; positive regulation of myeloid cell differentiation; regulation of fat cell differentiation; regulation of steroid biosynthetic process; female pregnancy; negative regulation of transcription from RNA polymerase II promoter; glucose homeostasis; positive regulation of luteinizing hormone secretion; negative regulation of appetite; positive regulation of tyrosine phosphorylation of Stat3 protein; response to insulin stimulus; response to vitamin E; positive regulation of MAPKKK cascade; regulation of cholesterol absorption; regulation of blood pressure; positive regulation of cell proliferation; positive regulation of ion transport; central nervous system neuron development; placenta development; positive regulation of cytokine production; cholesterol metabolic process; positive regulation of developmental growth; bile acid metabolic process; eating behavior; glucose metabolic process; adult feeding behavior; ovulation from ovarian follicle; leptin-mediated signaling pathway; negative regulation of vasoconstriction; tyrosine phosphorylation of STAT protein; fatty acid beta-oxidation; insulin secretion; glycerol biosynthetic process; energy reserve metabolic process; response to hypoxia; hormone metabolic process; regulation of gluconeogenesis; positive regulation of follicle-stimulating hormone secretion; positive regulation of insulin receptor signaling pathway; leukocyte tethering or rolling; regulation of insulin secretion; negative regulation of apoptosis Disease: Leptin Deficiency |
| NCBI Summary: | This gene encodes a protein that is secreted by white adipocytes, and which plays a major role in the regulation of body weight. This protein, which acts through the leptin receptor, functions as part of a signaling pathway that can inhibit food intake and/or regulate energy expenditure to maintain constancy of the adipose mass. This protein also has several endocrine functions, and is involved in the regulation of immune and inflammatory responses, hematopoiesis, angiogenesis and wound healing. Mutations in this gene and/or its regulatory regions cause severe obesity, and morbid obesity with hypogonadism. This gene has also been linked to type 2 diabetes mellitus development. [provided by RefSeq, Jul 2008] |
| UniProt Code: | P41159 |
| NCBI GenInfo Identifier: | 730218 |
| NCBI Gene ID: | 3952 |
| NCBI Accession: | P41159.1 |
| UniProt Secondary Accession: | P41159,O15158, Q56A88, |
| UniProt Related Accession: | P41159 |
| Molecular Weight: | 18,641 Da |
| NCBI Full Name: | Leptin |
| NCBI Synonym Full Names: | leptin |
| NCBI Official Symbol: | LEP |
| NCBI Official Synonym Symbols: | OB; OBS; LEPD |
| NCBI Protein Information: | leptin; obese protein; obesity factor; obese, mouse, homolog of; leptin (murine obesity homolog); leptin (obesity homolog, mouse) |
| UniProt Protein Name: | Leptin |
| UniProt Synonym Protein Names: | Obese protein; Obesity factor |
| Protein Family: | Leptin |
| UniProt Gene Name: | LEP |
| UniProt Entry Name: | LEP_HUMAN |
| Component | Quantity (96 Assays) | Storage |
| ELISA Microplate (Dismountable) | 8×12 strips | -20°C |
| Lyophilized Standard | 2 | -20°C |
| Sample Diluent | 20ml | -20°C |
| Assay Diluent A | 10mL | -20°C |
| Assay Diluent B | 10mL | -20°C |
| Detection Reagent A | 120µL | -20°C |
| Detection Reagent B | 120µL | -20°C |
| Wash Buffer | 30mL | 4°C |
| Substrate | 10mL | 4°C |
| Stop Solution | 10mL | 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
*Note: The below protocol is a sample protocol. Protocols are specific to each batch/lot. For the correct instructions please follow the protocol included in your kit.
Allow all reagents to reach room temperature (Please do not dissolve the reagents at 37°C directly). All the reagents should be mixed thoroughly by gently swirling before pipetting. Avoid foaming. Keep appropriate numbers of strips for 1 experiment and remove extra strips from microtiter plate. Removed strips should be resealed and stored at -20°C until the kits expiry date. Prepare all reagents, working standards and samples as directed in the previous sections. Please predict the concentration before assaying. If values for these are not within the range of the standard curve, users must determine the optimal sample dilutions for their experiments. We recommend running all samples in duplicate.
| Step | |
| 1. | Add Sample: Add 100µL of Standard, Blank, or Sample per well. The blank well is added with Sample diluent. Solutions are added to the bottom of micro ELISA plate well, avoid inside wall touching and foaming as possible. Mix it gently. Cover the plate with sealer we provided. Incubate for 120 minutes at 37°C. |
| 2. | Remove the liquid from each well, don't wash. Add 100µL of Detection Reagent A working solution to each well. Cover with the Plate sealer. Gently tap the plate to ensure thorough mixing. Incubate for 1 hour at 37°C. Note: if Detection Reagent A appears cloudy warm to room temperature until solution is uniform. |
| 3. | Aspirate each well and wash, repeating the process three times. Wash by filling each well with Wash Buffer (approximately 400µL) (a squirt bottle, multi-channel pipette,manifold dispenser or automated washer are needed). Complete removal of liquid at each step is essential. After the last wash, completely remove remaining Wash Buffer by aspirating or decanting. Invert the plate and pat it against thick clean absorbent paper. |
| 4. | Add 100µL of Detection Reagent B working solution to each well. Cover with the Plate sealer. Incubate for 60 minutes at 37°C. |
| 5. | Repeat the wash process for five times as conducted in step 3. |
| 6. | Add 90µL of Substrate Solution to each well. Cover with a new Plate sealer and incubate for 10-20 minutes at 37°C. Protect the plate from light. The reaction time can be shortened or extended according to the actual color change, but this should not exceed more than 30 minutes. When apparent gradient appears in standard wells, user should terminatethe reaction. |
| 7. | Add 50µL of Stop Solution to each well. If color change does not appear uniform, gently tap the plate to ensure thorough mixing. |
| 8. | Determine the optical density (OD value) of each well at once, using a micro-plate reader set to 450 nm. User should open the micro-plate reader in advance, preheat the instrument, and set the testing parameters. |
| 9. | After experiment, store all reagents according to the specified storage temperature respectively until their expiry. |
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. |
