| Description | Creatine Kinase (CK) is primarily found in tissues such as the heart, muscle, and brain. It reversibly catalyzes the transphosphorylation reaction between creatine and ATP, playing a vital role in energy transfer, muscle contraction, and ATP regeneration. It is a crucial clinical indicator for Creatine Kinase (CK) is primarily found in tissues such as the heart, muscle, and brain. It reversibly catalyzes the transphosphorylation reaction between creatine and ATP, playing a vital role in energy transfer, muscle contraction, and ATP regeneration. It is a crucial clinical indicator for diagnosing heart and brain diseases.Assay PrincipleCK catalyzes the conversion of Phosphocreatine and ADP to Creatine and ATP. Hexokinase then catalyzes the reaction of ATP with Glucose to form Glucose-6-Phosphate (G6P). Subsequently, Glucose-6-Phosphate Dehydrogenase (G6PDH) catalyzes the oxidation of G6P with NADP⁺ to generate NADPH, leading to an increase in absorbance at 340 nm. Component100TStorageExtraction Buffer100 mL2-8℃Reagent 11EA2-8℃. Store in the dark.Reagent 210 mL2-8℃Reagent 1: Powder in one bottle. Store at 4°C protected from light. Dissolve in 10 mL distilled water before use.Working Solution: Prepare immediately before use by mixing Reagent 1 and Reagent 2 at a 1:1 ratio. Incubate the Working Solution at 37°C for 2 minutes prior to use.Required Materials and Equipment (Not Provided)Balance, refrigerated centrifuge, constant temperature water bath, microplate reader, 96-well plate, and distilled water.Crude Enzyme Extraction:Tissue Samples: Homogenize the tissue on ice in Extraction Buffer at a ratio of 1:5-10 (w/v) (e.g., weigh ~0.1g tissue, add 1 mL Extraction Buffer). Centrifuge the homogenate at 10,000 g, 4°C for 15 min. Collect the supernatant for assay.Serum Samples: assay directly.Assay Procedure:Preheat the microplate reader for at least 30 minutes. Set the wavelength to 340 nm.Pipette 40 µl of sample and 60 µl of distilled water into a well of the 96-well plate. Add 100 µl of the pre-warmed (37°C) Working Solution. Mix immediately and record the initial absorbance (A₁) and the absorbance after exactly 1 minute (A₂) at 37°C. Calculate ΔA = A₂ - A₁.CK Enzyme Activity Calculation:General Parameters:ε (NADPH molar extinction coefficient) = 6220 L/mol/cmd (Light path for 96-well plate) = 0.5 cmVₜₒₜₐₗ (Total reaction volume) = 0.2 mL (200 µL)Vₛₐₘₚₗₑ (Sample volume in reaction) = 0.04 mL (40 µL)T (Reaction time) = 1 minCpr (Sample protein concentration, mg/mL)W (Sample mass, g)Vₛₐₘₚₗₑₜₒₜₐₗ (Total extract volume) = Assumed 1 mL for tissue calculations1. Based on Tissue Protein Content:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per mg of protein at 37°C, pH 7.0.Calculation:CK Activity (nmol/min/mg prot) = [ΔA / (ε × d)] × Vₜₒₜₐₗ ÷ (Vₛₐₘₚₗₑ × Cpr) ÷ TSimplified Formula: CK (nmol/min/mg prot) = 1608 × ΔA ÷ Cpr2. Based on Tissue Sample Mass:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per gram of fresh tissue at 37°C, pH 7.0.Calculation:CK Activity (nmol/min/g fresh weight) = [ΔA / (ε × d)] × Vₜₒₜₐₗ ÷ (Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ × W) ÷ TSimplified Formula: CK (nmol/min/g fresh weight) = 1608 × ΔA ÷ W3. Based on Serum:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per liter of serum at 37°C, pH 7.0.Calculation:CK Activity (nmol/min/L) = [ΔA / (ε × d)] × Vₜₒₜₐₗ ÷ Vₛₐₘₚₗₑ ÷ TSimplified Formula: CK (nmol/min/L) = 1608 × ΔANotesBefore formal assay, it is essential to perform a pilot test with 2-3 samples expected to have significant differences in activity.The prepared Working Solution is stable at 4°C for 7 days. However, it is recommended to use it as soon as possible after preparation.CK in serum is unstable. Determine the activity as soon as possible after sample collection. It can be stored protected from light at 4°C for up to 24 hours.Sample protein content needs to be determined separately. A BCA Protein Assay Kit can be used for this purpose.If the OD value is greater than 0.5, dilute the sample appropriately with Extraction Buffer and account for the dilution factor (D) in the calculation formulas (e.g., 1608 × ΔA × D ÷ Cpr)... Read More | Product introduction：This kit uses uniqcell lysis and heme / protein precipitation technology, combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of purifying genomic DNA.Scope of application：Nucleic acid extraction and purification | This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. Purified lactose antibodies were coated on a microplate to produce solid-phase antibodies. Lactose was added to the microplate of the coated monoclonal antibody, along with HRP labeled lactose antigens, to compete for binding. After thorough washing, the substrate TMB was added for colorimetry. The depth of sample color is negatively correlated with the content of lactose in the sample. Measure the absorbance (OD value) at a wavelength of 450nm using an enzyme-linked immunosorbent assay (ELISA) reader, and calculate the content of lactose in the sample through a standard curve.Kit composition:130times concentrated washing solution20ml×1 bottle8.1Standard S1（80µg/L）0.5ml×1bottle2Enzyme-linked immunosorbent assay6ml×1 bottle8.2Standard S2（40µg/L）0.5ml×1bottle3Enzyme labeling coated plate96 holes x 1 pieces8.3Standard S3（20µg/L）0.5ml×1bottle4Color reagent A solution6ml×1 bottle8.4Standard S4（10µg/L）0.5ml×1bottle5Color developer B solution6ml×1 bottle8.5Standard S5（5µg/L）0.5ml×1bottle6Stop solution6ml×1 bottle9Instructions1 copy7Sample Diluent6ml×1 bottle10Microplate Sealers2 sheetsSpecimen requirements:1. Specimen processing:(1) After collecting the water sample, it is repeatedly freeze-thawed three times at -20 ℃, and then filtered through glass fiber for future reference(2) The tissue samples should be extracted using butanol: methanol: water (5:25:70 V: V: V), or extracted according to relevant literature. The experiment should be conducted as soon as possible after extraction. If the experiment cannot be conducted immediately, the specimen can be stored at -20 ℃ for future reference2. Samples containing NaN3 cannot be detected as NaN3 inhibits the activity of horseradish peroxidase (HRP).Operation steps:1. Sample addition: Set up standard wells, blank wells (blank control wells do not include samples and enzyme-linked immunosorbent assay reagents, the other steps are the same), and sample wells to be tested. Add 50 microliters to the standard well on the enzyme-linked immunosorbent assay (ELISA) plate, and first add 40 diluents to the sample well to be tested µ l. Then add 10 more samples to be tested µ L (The final dilution of the sample is 5 times). Add the sample to the bottom of the enzyme-linked immunosorbent assay (ELISA) plate well, avoiding touching the well wall as much as possible. Gently shake and mix well.2. Enzyme addition: Add 50 enzyme labeled reagents to each well µ l. Excluding blank holes.3. Warm incubation: Seal the plate with a sealing film and incubate at 37 ℃ for 60 minutes.4. Solution preparation: Dilute 30 times the concentrated washing solution with distilled water and set aside for later use5. Washing: Carefully remove the sealing film, discard the liquid, shake dry, fill each well with washing solution, let it stand for 30 seconds, then discard. Repeat this process 5 times and pat dry.6. Color development: Add color development agent A50 to each well first µ l. Add color developer B50 again µ l. Gently shake and mix well, and develop color at 37 ℃ in the dark for 15 minutes7. Termination: Add 50% termination fluid to each hole µ l. Terminate the reaction (at this point, the blue color immediately turns yellow).8. Measurement: Zero the blank hole and sequentially measure the absorbance (OD value) of each hole at a wavelength of 450nm. The measurement should be conducted within 15 minutes after adding the termination solution.Calculation:Draw a standard curve on a coordinate paper with the concentration of the standard substance as the x-axis and the OD value as the y-axis. Based on the OD value of the sample, determine the corresponding concentration from the standard curve; Multiply it by the dilution factor; Alternatively, a linear regression equation can be used to calculate the standard curve using the concentration and OD value of the standard substance. The OD value of the sample can be substituted into the equation to calculate the sample concentration, which is then multiplied by the dilution factor to obtain the actual concentration of the sample.Notes:1. The kit should be balanced at room temperature for 15-30 minutes before use when taken out from the cold storage environment. If the enzyme coated plate is not used up after opening, the Flat noodles should be stored in a sealed bag.2. Concentrated detergent may precipitate crystals. When diluted, it can be heated in a water bath to aid in dissolution. Washing does not affect the results.3. A sampler should be used for each step of sample addition, and its accuracy should be regularly calibrated to avoid experimental errors. It is best to control the sample addition time within 5 minutes. If there are a large number of specimens, it is recommended to use a firing gun for sample addition.4. Please make a standard curve at the same time as each measurement, preferably with a re hole. If the content of the substance to be tested in the sample is too high (the OD value of the sample is greater than the OD value of the first well of the standard well), please dilute the sample diluent by a certain multiple (n times) before measurement. When calculating, please multiply the total dilution multiple (x n x 5).5. The sealing film is only for one-time use to avoid cross contamination.6. Please store the substrate in dark.7. Strictly follow the instructions and determine the test results based on the reading of the enzyme-linked immunosorbent assay (ELISA) reader8. All samples, washing liquids, and various waste should be treated as infectious substances.9. The components of this reagent with different batch numbers shall not be mixed.Detection range:two µ G/L-90 µ G/L... Read More | Product introduction：Griess reagent can be used for spectrophotometric detection of nitrite. The reagent contains two chemicals, sulfonic acid and n- (1-naphthyl) ethylenediamine. Under acidic conditions, sulfamic acid is converted into diazonium salt by nitrite, which can form a highly Product introduction：Griess reagent can be used for spectrophotometric detection of nitrite. The reagent contains two chemicals, sulfonic acid and n- (1-naphthyl) ethylenediamine. Under acidic conditions, sulfamic acid is converted into diazonium salt by nitrite, which can form a highly colored azo dye with n- (1-naphthyl) ethylenediamine. This dye can be detected at 548 nm: because no is extremely unstable, it is oxidized to form nitrite and nitrate. Griess indirectly reflects the content of no by detecting the content of nitrite.Matters needing attention：1. before using Griess reagent, return it to room temperature and check the solution for precipitation. If Griess reagent I contains sediment when taken out, it can be placed in a 37 ℃ water bath until the sediment dissolves. 2. this product is potentially harmful. Avoid prolonged or repeated exposure. Avoid entering eyes, skin or clothing. Please wear lab clothes and disposable gloves for operation.Scope of application：No detectionComponent：Instruction：1.Griess Reagent I and II were taken out to restore the room temperature.2.Standard dilution : The standard NaNO2 ( 1-100 µM ) was diluted with the solution used for the sample to be tested. The standard was diluted to 1 µM, 10 µM, 20 µM, 40 µM, 80 µM and 100 µM, and 100 µL standard was added to each well. If the sample concentration is too low, the range of the standard curve can be appropriately reduced ( 1 µM, 2 µM, 3 µM, 4 µM, 6 µM, 8 µM, 10 µM ).3.Sample detection :( 1 ) According to the total volume of 200 µL / hole, 100 µL / hole sample was added to the 96-well plate ; if the sample is the supernatant of the culture medium, it can be sampled directly, and if there is sediment, the supernatant should be taken after centrifugation. If the sample is a cell or tissue, it can be quickly lysed by freeze-thaw, and then centrifuged to obtain the supernatant. The volume of less than 100 µL can be diluted with diH2O or 0.9 % NaCl ( corresponding standards also need to be diluted with diH2O or 0.9 % NaCl ).( 2 ) According to 50 µL / hole, Griess Reagent I was added to each hole.( 3 ) According to 50 µL / hole, Griess Reagent II was added to each hole.( 4 ) The absorbance was measured at 540 nm. If there is no 540 nm filter, 520-560 nm filter can also be. If there is no microplate reader or a suitable filter, the concentration of nitric oxide in the sample can also be determined by visual colorimetry. A more precise concentration gradient is required for the standard when visual colorimetric... Read More | Cell viability and cytotoxicity assays are usually used for drug screening and compound cytotoxicity testing. The CCK-8 kit uses highly water-soluble tetrazolium salt ( called WST-8 ) to produce water-soluble WST-8 for cell proliferation and cytotoxicity assays. Unlike MTT, WST-8 and WST-8 have no Cell viability and cytotoxicity assays are usually used for drug screening and compound cytotoxicity testing. The CCK-8 kit uses highly water-soluble tetrazolium salt ( called WST-8 ) to produce water-soluble WST-8 for cell proliferation and cytotoxicity assays. Unlike MTT, WST-8 and WST-8 have no cytotoxicity in cell culture medium, so multiple downstream experiments can be performed using the same detection plate. CCK-8 method is a convenient colorimetric method for the determination of cell viability. It does not need the solubilization process and only needs the least steps to provide the results. The CCK-8 method can be used for the determination of 96-well microplates and high-throughput screening of 384-well microplates. Advantage：At present, the commercially available liquid CCK-8 kits generally have defects such as harsh storage conditions ( -4C or -20 ), unstable use in different pH ranges, and easy deterioration ( discoloration or precipitation ). The solid instant CCK-8 kit adopts a new formula and Swiss process, which overcomes these shortcomings of the liquid CCK-8 kit. It can be stored at room temperature for a long time ( > 3 years ), ready to use, stable in a wide pH range, and the experimental results are more reliable. Compared with the liquid CCK-8 kit, the solid-soluble CCK-8 kit has higher sensitivity and the biological response time is shortened by half.Application scope:It can be used for drug screening, cell proliferation assay, cytotoxicity assay, tumor drug sensitivity test and activity detection of biological factors. Operating instructions:This reagent kit can be used for drug screening, cell proliferation assay, cytotoxicity assay, tumor drug sensitivity assay, and activity detection of biological factors.1. Carefully and slowly tear along the gap in the packaging bag;2. Pour all the powder in the bag into a clean container containing 10mL of ultrapure water, shake continuously for 1 minute, and use it when the solid is completely dissolved;3. Unused reagents must be stored at low temperatures below 4 ℃.Equipment required for testing:Enzyme reader 96 well plate with 450-490 nm filter;Carbon dioxide incubator;96 well plate, sterilized transparent plate for cell detection;Multi channel pipette (8 or 12 channels: 10-100 µ l);Blood cell counter or cell counter.Cell viability testing:1. Inoculate cell suspension (100 µ l/well) into a 96 well plate and pre culture the plate in a carbon dioxide incubator for 24 hours (37 ℃, 5% CO2);2. Add 10 µ l of CCK-8 solution to each well (be careful not to generate bubbles in the well as it may affect the reading of OD value);3. Incubate the culture plate in the incubator for 1-4 hours;4. Measure the absorbance at 450 nm using an enzyme-linked immunosorbent assay (ELISA) reader;5. If the OD value is not determined temporarily, 10 µ l of 0.1M HCI solution or 1% w/v SDS solution can be added to each well, and the culture plate can be covered and stored in the dark at room temperature. Within 24 hours of measurement, the absorbance will not change.Cell proliferation toxicity testing:1. Inoculate cell suspension (100 µ l/well) into a 96 well plate and pre culture the plate in an incubator for 24 hours (37 ℃, 5% CO2);2. Add 10ul of different concentrations of the substance to be tested to the culture plate;3. Incubate the culture plate in the incubator for an appropriate period of time (e.g. 6, 12, 24, or 48 hours);4. Add 10 µ l of CCK-8 solution to each well (be careful not to generate bubbles in the well as they may affect the reading of the OD value);5. Incubate the culture plate in the incubator for 1-4 hours;6. Measure the absorbance at 450nm using an enzyme-linked immunosorbent assay (ELISA) reader;7. If the OD value is not determined temporarily, 10 µ l of 0.1M HCI solution or 1% w/v SDS solution can be added to each well, and the culture plate can be covered and stored in the dark at room temperature. Within 24 hours of measurement, the absorbance will not change.Calculation method for cell survival rate/inhibition rate:Cell survival rate=[As Ab)/(Ac Ab)] x 100%Inhibition rate=[(Ac As)/(Ac Ab)] x 100%As: absorbance of experimental wells (including cells, culture medium, CCK-8 solution, and drug solution);Ac: absorbance of control wells (including cells, culture medium, CCK-8 solution, without drugs);Ab: Blank well absorbance (including culture medium and CCK-8 solution, excluding cells and drugs).Points for attention： 1.Unused reagents must be stored at low temperature below 4 °C, and stored in the dark at-20 °C for two years after unpacking, so as to avoid repeated thawing ; 2.The culture time of CCK-8 is generally 1-4 hours, but the naked eye can be taken out to observe the color degree in about 30 minutes. According to the cell type, the conditions need to be explored. The best reaction time of CCK-8 is based on the best time of specific color development.3. It is recommended to do a few holes to explore the number of inoculated cells and the culture time after adding CCK-8 reagent ; 3.The WST-8 in this kit will react with reducing agents ( such as some antioxidants ) to interfere with the detection. Before the cell proliferation-toxicity test, the background OD can be checked to confirm whether there is a reducing agent in the substance to be tested. If the effect of reducing agent needs to be removed, the fresh medium can be replaced before adding CCK-8 ( remove the medium, wash the cells twice with the medium, and then add the new medium ) ; 4.Phenol red in the medium does not affect the experimental results, and the absorbance of phenol red can be eliminated by deducting the absorbance of the background in the blank hole during calculation, so it will not affect the detection. 5.It is recommended to use a multi-channel pipette to reduce the difference between parallel holes. When adding CCK-8 reagent, it is recommended to add it obliquely to the wall of the culture plate, not to insert it under the liquid surface of the medium, which is easy to produce bubbles and interfere with OD determination. 6.If the drug contains metal, it has an effect on the color of CCK-8. The final concentration of 1mM lead chloride, ferric chloride and copper sulfate will inhibit the color reaction of 5 %, 15 % and 90 %, and reduce the sensitivity. If the final concentration is 10mM, the color reaction will be 100 % inhibited ; 7.When using a 96-well plate for detection, if the cell culture time is long, attention should be paid to the evaporation problem. On the one hand, because a circle around the 96-well plate is the easiest to evaporate, the method of discarding the surrounding circle can be adopted, and the same amount of PBS, water or culture medium can be added. On the other hand, the 96-well plate can be placed near the water source in the incubator to alleviate evaporation ; 8.When using standard 96-well plates, the minimum inoculation amount of adherent cells is at least 1,000 cells / well ( 100µl medium ). The sensitivity of detecting white blood cells is relatively low, so it is recommended that the inoculation amount should not be less than 2,500 cells / well ( 100 µl medium ). If you want to use a 24-well plate or a 6-well plate experiment, first calculate the corresponding inoculation amount per well, and add the CCK-8 solution according to 10 % of the total volume of the medium per well ; 9.Cell culture time varies according to the type and number of cells ( per well ), usually the color of white blood cells is weak, requiring a longer culture time ( 4 hours ) and a large number of cells ( ~ 105 cells / well ) ; 10.CCK-8 reagent is very low toxic to cells. The continuous reaction between it and dehydrogenase in living cells makes the color of the solution deepen and the OD value increase. The following methods can terminate the CCK-8 reaction ( 96-well plate ) : a ) After the color reaction, the culture plate was placed in a refrigerator at 4 ° C ; b ) 10µL 0.1MHCL solution was added to each well ; c ) 10 µL 1 % ( w / v ) SDS ( sodium dodecyl sulfate ) solution was added to each well. After the reaction stopped, the OD value should be measured within 24 hours. 11.To determine the specific number of cells, it is recommended to do the standard curve at the same time... Read More |