Description
Human Cathepsin D (CTSD) ELISA Kit
The Human Cathepsin D (CTSD) ELISA Kit is a powerful tool for researchers studying the role of Cathepsin D in various biological processes. Cathepsin D is a lysosomal protease involved in protein degradation and plays a crucial role in cell homeostasis and differentiation.This ELISA kit is designed for the accurate detection of Cathepsin D levels in human serum, plasma, and cell culture supernatants. With high sensitivity and specificity, this kit provides reliable and reproducible results, making it suitable for a wide range of research applications.
Cathepsin D has been implicated in various diseases, including cancer, Alzheimer's disease, and other neurodegenerative disorders. By measuring Cathepsin D levels, researchers can gain valuable insights into disease mechanisms and potential therapeutic targets.Overall, the Human Cathepsin D (CTSD) ELISA Kit is a valuable tool for researchers seeking to understand the role of Cathepsin D in health and disease. Its high sensitivity and accuracy make it an essential addition to any laboratory conducting research in this area.
| Product Name: | Human Cathepsin D (CTSD) ELISA Kit |
| SKU: | HUEB0357 |
| Size: | 96T |
| Target: | Human Cathepsin D (CTSD) |
| Synonyms: | CPSD |
| Assay Type: | Sandwich |
| Detection Method: | ELISA |
| Reactivity: | Human |
| Detection Range: | 0.156-10ng/mL |
| Sensitivity: | 0.078ng/mL |
| Intra CV: | 4.9% | ||||||||||||||||||||
| Inter CV: | 8.5% | ||||||||||||||||||||
| Linearity: |
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| Recovery: |
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| Function: | Acid protease active in intracellular protein breakdown. Plays a role in APP processing following cleavage and activation by ADAM30 which leads to APP degradation (PubMed:27333034). Involved in the pathogenesis of several diseases such as breast cancer and possibly Alzheimer disease. |
| Uniprot: | P07339 |
| Sample Type: | Serum, plasma, tissue homogenates, cell culture supernates and other biological fluids |
| Specificity: | Natural and recombinant human Cathepsin D |
| Sub Unit: | Consists of a light chain and a heavy chain (PubMed:8393577, PubMed:1426530). Interacts with ADAM30; this leads to activation of CTSD (PubMed:27333034). |
| Research Area: | Neurosciences |
| Subcellular Location: | Lysosome Melanosome Secreted Extracellular space Identified by mass spectrometry in melanosome fractions from stage I to stage IV. In aortic samples, detected as an extracellular protein loosely bound to the matrix (PubMed:20551380). |
| Storage: | Please see kit components below for exact storage details |
| Note: | For research use only |
| UniProt Protein Function: | CTSD: Acid protease active in intracellular protein breakdown. Involved in the pathogenesis of several diseases such as breast cancer and possibly Alzheimer disease. Consists of a light chain and a heavy chain. Belongs to the peptidase A1 family. |
| UniProt Protein Details: | Protein type:Autophagy; Motility/polarity/chemotaxis; Protease; EC 3.4.23.5 Chromosomal Location of Human Ortholog: 11p15.5 Cellular Component: extracellular matrix; extracellular space; lysosomal lumen; lysosome; melanosome; extracellular region Molecular Function:protein binding; aspartic-type endopeptidase activity Biological Process: collagen catabolic process; extracellular matrix disassembly; extracellular matrix organization and biogenesis; antigen processing and presentation of exogenous peptide antigen via MHC class II; proteolysis Disease: Ceroid Lipofuscinosis, Neuronal, 10 |
| NCBI Summary: | This gene encodes a lysosomal aspartyl protease composed of a dimer of disulfide-linked heavy and light chains, both produced from a single protein precursor. This proteinase, which is a member of the peptidase C1 family, has a specificity similar to but narrower than that of pepsin A. Transcription of this gene is initiated from several sites, including one which is a start site for an estrogen-regulated transcript. Mutations in this gene are involved in the pathogenesis of several diseases, including breast cancer and possibly Alzheimer disease. [provided by RefSeq, Jul 2008] |
| UniProt Code: | P07339 |
| NCBI GenInfo Identifier: | 115717 |
| NCBI Gene ID: | 1509 |
| NCBI Accession: | P07339.1 |
| UniProt Secondary Accession: | P07339,Q6IB57, |
| UniProt Related Accession: | P07339 |
| Molecular Weight: | 44,552 Da |
| NCBI Full Name: | Cathepsin D |
| NCBI Synonym Full Names: | cathepsin D |
| NCBI Official Symbol: | CTSD |
| NCBI Official Synonym Symbols: | CPSD; CLN10; HEL-S-130P |
| NCBI Protein Information: | cathepsin D; lysosomal aspartyl protease; lysosomal aspartyl peptidase; ceroid-lipofuscinosis, neuronal 10; epididymis secretory sperm binding protein Li 130P |
| UniProt Protein Name: | Cathepsin D |
| Protein Family: | Cathepsin |
| UniProt Gene Name: | CTSD |
| UniProt Entry Name: | CATD_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. |
