Purpose | This immunoassay kit allows for the in vitro quantitative determination of mouse SHBG concentrations in serum, plasma and other biological fluids. |
Sample Type | Serum, Plasma, Biological Fluids |
Analytical Method | Quantitative |
Detection Method | Colorimetric |
Specificity | This assay recognizes recombinant and natural mouse SHBG. |
Cross-Reactivity (Details) | No significant cross-reactivity or interference was observed. |
Sensitivity |
< 0.039 nmol/L The sensitivity of this assay, or Lower Limit of Detection (LLD) was defined as the lowest detectable concentration that could be differentiated from zero. |
Characteristics | Mus musculus,Mouse,Sex hormone-binding globulin,SHBG,Sex steroid-binding protein,SBP,Testis-specific androgen-binding protein,ABP,Shbg |
Components | Reagent (Quantity): Assay plate (1), Standard (2), Sample Diluent (1×20ml), Assay Diluent A (1×10ml), Assay Diluent B (1×10ml), Detection Reagent A (1×120 μl), Detection Reagent B (1×120 μl), Wash Buffer(25 x concentrate) (1×30ml), Substrate (1×10ml), Stop Solution (1×10ml), Plate sealer for 96 wells (5), Instruction (1) |
Material not included | Luminometer. Pipettes and pipette tips. EP tube Deionized or distilled water. |
Alternative Name | Shbg (SHBG ELISA Kit Abstract) |
Background | Sex hormone-binding globulin (SHBG) is a glycoprotein that binds to sex hormones, specifically testosterone and estradiol. Other steroid hormones such as progesterone, cortisol, and other corticosteroids are bound by transcortin. These sex hormones circulate in the bloodstream, bound mostly to SHBG and to some degree bound to serum albumin. Only a small fraction is unbound, or ",free,", and thus biologically active and able to enter a cell and activate its receptor. The SHBG inhibits the function of these hormones. Thus bioavailability of sex hormones is influenced by the level of SHBG. SHBG is produced by the liver cells and is released into the bloodstream. Other sites that produce SHBG are the brain, uterus, and placenta and vagina. In addition SHBG is produced by the testes, testes-produced SHBG is also called androgen-binding protein. The gene for SHBG is located on chromosome 17. SHBG levels appear to be controlled by a delicate balance of enhancing and inhibiting factors. Its level is decreased by high levels of insulin and insulin-like growth factor-I (IGF-I). Also, high androgen levels decrease SHBG, while high estrogen and thyroxine levels increase it. Conditions with low SHBG include polycystic ovary syndrome, diabetes, and hypothyroidism. Conditions with high SHBG include pregnancy, hyperthyroidism, and anorexia nervosa. There has recently been research to link high SHBG levels with breast and testicular cancer as well. |
Pathways | Hormone Transport |
Sample Volume | 100 μL |
Plate | Pre-coated |
Protocol | The microtiter plate provided in this kit has been pre-coated with an antibody specific to SHBG. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated polyclonal antibody preparation specific for SHBG. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB substrate solution is added to each well. Only those wells that contain SHBG, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm 2 nm. The concentration of SHBG in the samples is then 2 determined by comparing the O.D. of the samples to the standard curve. |
Reagent Preparation |
Bring all reagents to room temperature before use. Wash Buffer - If crystals have formed in the concentrate, warm to room temperature and mix gently until the crystals have completely dissolved. Dilute 30 mL of Wash Buffer Concentrate into deionized or distilled water to prepare 750 mL of Wash Buffer. Standard - Reconstitute the Standard with 1.0 ml of Sample Diluent. This reconstitution produces a stock solution of 10 nmol/L. Allow the standard to sit for about 10 minutes with gentle agitation prior to making serial dilutions (Making serial dilution in the wells directly is not permitted). The undiluted standard serves as the highest standard (10 nmol/L). The Sample Diluent serves as the zero standard (0 nmol/L). nmol/L 10 5 2.5 1.25 0.625 0.312 0.156 0 Detection Reagent A and B - Dilute to the working concentration using Assay Diluent A or B (1:100), respectively. |
Sample Collection | Serum - Use a serum separator tube and allow samples to clot for 30 minutes before centrifugation for 20 minutes at approximately 1000 g. Remove serum and assay immediately or aliquot and store samples at -20 or -80 . Plasma - Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples for 15 minutes at 1000 g at 2 - 8 within 30 minutes of collection. Store samples at -20 or -80 . Avoid repeated freeze-thaw cycles. Other biological fluids - Remove particulates by centrifugation and assay immediately or aliquot and store samples at -20 or -80 . Avoid repeated freeze-thaw cycles. Sample preparation - Serum/plasma samples require a 10 fold dilution. A suggested 10-fold dilution is 100uL Sample + 900uL Sample Diluent. Sample should be diluted by 0.1 M PBS(PH=7.0-7.2). Note: Serum and plasma to be used within 7 days may be stored at 2-8 , otherwise samples must stored at -20 ( 1 month) or -80 ( 2 months) to avoid loss of bioactivity and contamination. Avoid freeze-thaw cycles. When performing the assay slowly bring samples to room temperature. |
Assay Procedure |
Allow all reagents to reach room temperature (Please do not dissolve the reagents at 37 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 4 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 particular experiments. |
Calculation of Results |
Average the duplicate readings for each standard, control, and sample and subtract the average zero standard optical density. Create a standard curve by reducing the data using computer software capable of generating a four parameter logistic (4-PL) curve-fit. As an alternative, construct a standard curve by plotting the mean absorbance for each standard on the x-axis against the concentration on the y-axis and draw a best fit curve through the points on the graph. The data may be linearized by plotting the log of the SHBG concentrations versus the log of the O.D. and the best fit line can be determined by regression analysis. It is recommended to use some related software to do this calculation, such as curve expert 13.0. This procedure will produce an adequate but less precise fit of the data. If samples have been diluted, the concentration read from the standard curve must be multiplied by the dilution factor. |
Restrictions | For Research Use only |
Handling Advice |
1. The kit should not be used beyond the expiration date on the kit label. 2. Do not mix or substitute reagents with those from other lots or sources. 3 3. If samples generate values higher than the highest standard, further dilute the samples and repeat the assay. Any variation in standard diluent, operator, pipetting technique, washing technique,incubation time or temperature, and kit age can cause variation in binding. 4. This assay is designed to eliminate interference by soluble receptors, ligands, binding proteins, and other factors present in biological samples. Until all factors have been tested in the Immunoassay, the possibility of interference cannot be excluded. |
Storage | 4 °C/-20 °C |
Storage Comment | The Standard, Detection Reagent A, Detection Reagent B and the 96-well strip plate should be stored at -20 °C upon being received. The other reagents can be stored at 4 °C. |