| Description | Blood potassium plays a crucial role in maintaining normal osmotic pressure, acid-base balance, sugar and protein metabolism, and ensuring normal neuromuscular function. Its concentration is closely related to various important physiological functions. Abnormally high or low levels can disrupt Blood potassium plays a crucial role in maintaining normal osmotic pressure, acid-base balance, sugar and protein metabolism, and ensuring normal neuromuscular function. Its concentration is closely related to various important physiological functions. Abnormally high or low levels can disrupt normal physiological activities. Hyperkalemia increases neuromuscular excitability but decreases myocardial excitability, leading to bradycardia. Hypokalemia can cause muscle weakness or even flaccid paralysis, increase myocardial excitability, and result in tachycardia, arrhythmias, or even cardiac arrest during systole.Detection Principle: Potassium ions (K⁺) in serum react with sodium tetraphenylboron to form water-insoluble potassium tetraphenylboron. The turbidity produced is directly proportional to the potassium ion concentration within a certain range. The serum potassium ion content is determined by measuring this turbidity.Applicable Sample: SerumG1501769Component96 TStorageG1501769AExtraction Buffer50 mL2-8℃G1501769BReagentⅠ2.4 mL2-8℃G1501769CReagentⅡ1EA2-8℃. Store in the dark.G1501769DReagentⅢ20 mL2-8℃G1501769EStandard1 mL2-8℃Note: Before formal testing, it is recommended to perform a preliminary test with 2-3 samples expected to have significant differences.User-Prepared Instruments and ReagentsMicroplate reader or visible spectrophotometer (capable of measuring absorbance at 520 nm)96-well plate or micro glass cuvettes, adjustable micropipettes and tipsCentrifugeDeionized water, Concentrated Sulfuric AcidExperimental Procedure1. Reagent PreparationReagent NameReagent PreparationNotesExtraction Buffer/Slightly irritating. Use appropriate personal protective equipment during handling.Working Extraction BufferPrepare before use: Mix Extraction Buffer (mL) and Concentrated Sulfuric Acid (µL) in a 5:12 ratio as needed. Prepare freshly for each use.If precipitate forms, prepare a new batch.Reagent Ⅱ Working SolutionPrepare before use: Add the entire contents of Reagent Ⅰ into the Reagent Ⅱ vial. Mix well. This is the Reagent Ⅱ Working Solution.Can be stored at 4°C protected from light for one week.ReagentⅢPreheat in a 25°C water bath for at least 30 minutes before use./StandardReady-to-use; Equilibrate to room temperature before use.Store at 4°C.2. Sample PreparationSerum Pretreatment: Take a microcentrifuge tube. Sequentially add 50 µL of serum and 450 µL of Working Extraction Buffer. Mix thoroughly. Centrifuge at 8,000 rpm for 10 minutes at room temperature (approximately 25°C). Collect the supernatant for assay.3. Assay Steps3.1 Preheat the microplate reader or visible spectrophotometer for at least 30 minutes. Set the wavelength to 520 nm. For spectrophotometers, zero the instrument with deionized water.3.2 Assay Procedure (perform in a 96-well plate or micro glass cuvette):ReagentBlank Well (µL)Standard Well (µL)Test Well (µL)Deionized Water4000Standard0400Supernatant0040Reagent Ⅱ Working Solution202020Mix well and let stand for 5 minutes.ReagentⅢ1401401403.3 Mix well after addition. Measure the absorbance at 520 nm. Record the absorbance of the Blank well as A blank, the Standard well as A standard, and the Test well as A test. Note:The Blank and Standard tubes only need to be set up 1-2 times.It is recommended to perform a preliminary test with 2-3 samples expected to have significant differences before the formal experiment. If A <sub> test </sub> is less than 0.02, consider increasing the sample volume appropriately. If A <sub> test </sub> is greater than 1.1, further dilute the sample with Working Extraction Buffer (multiply the result by the dilution factor) or reduce the sample volume used for extraction.4. Calculation of ResultsNote: We provide both the derived formula and a simplified formula. They are equivalent. It is recommended to use the simplified formula in bold for final calculation.Blood Potassium Concentration (mmol/L) = [C Standard × (A test - A blank ) ÷ (A standard - A blank )] × n = 5 × (A test - A blank ) ÷ (A standard - A blank )Parameter Definitions:C Standard : 0.5 mmol/Ln: Sample dilution factor (10)Precautions1. Before formal testing, it is recommended to perform a preliminary test with 2-3 samples expected to have significant differences.2. Biochemical reagents are generally irritating and potentially biologically toxic. For your safety and health, please use appropriate biosafety precautions throughout the experiment, including wearing lab coats, masks, gloves, and head covers. Perform experiments in a fume hood or biosafety cabinet.3. This product is for research use only. Not for use in clinical diagnosis... Read More | DescriptionCholesteryl ester transfer protein (CETP) is present in normal human plasma and transfers neutral lipids from high density lipoproteins (HDL) to very low density lipoprotein (VLDL) and low density lipoprotein (LDL). CETP plays an important role in lipoprotein metabolism and influences theDescriptionCholesteryl ester transfer protein (CETP) is present in normal human plasma and transfers neutral lipids from high density lipoproteins (HDL) to very low density lipoprotein (VLDL) and low density lipoprotein (LDL). CETP plays an important role in lipoprotein metabolism and influences the reverse cholesterol transport pathway.Preparation instructionsSuitable for high-throughput screening (HTS), mechanism of action (MOA) studies, and structure-activity relationship (SAR) work in CETP sources.PrincipleThe CETP RP Activity Assay uses a proprietary substrate that enables the detection of CETP-mediated neutral lipid mass transfer. The method is useful for measuring CETP activity in recombinant protein (RP) or purified CETP samples and has a high D... Read More | Inquire | This kit combines efficient guanidine isothiocyanate lysis technology with silicon matrix membrane purification technology to efficiently extract total RNA from animal cells and tissues. The starting sample usually has a maximum of 30 mg of tissue or 1 x 107 cells. This reagent kit can also recover This kit combines efficient guanidine isothiocyanate lysis technology with silicon matrix membrane purification technology to efficiently extract total RNA from animal cells and tissues. The starting sample usually has a maximum of 30 mg of tissue or 1 x 107 cells. This reagent kit can also recover partially purified RNA, RNA obtained from in vitro transcription and enzymatic reactions. This reagent kit can extract and purify high-quality RNA with a molecular weight greater than 200 bases, with almost no DNA residue. If RNA experiments are to be conducted that are highly sensitive to trace amounts of DNA, residual DNA can be digested and removed on a column using DNase I without RNase. The extracted RNA can be used for downstream experiments such as RT-PCR, Northern Blot, Dot Blot, etc. R666020Component50 TStorageR666020ABuffer RL35 mLRTR666020BBuffer RW140 mLRTR666020CBuffer RW2 (concentrate)11 mLRTR666020DRNase-Free Water10 mLRTR666020ESpin Columns RM with Collection Tubes50 setsRTR666020FRNase-Free Centrifuge Tubes (1.5 mL)50 EART Self prepared reagents: β- Mercaptoethanol, anhydrous ethanol (newly opened or dedicated for RNA extraction).Preparation and important precautions before the experimentTo prevent RNase pollution, attention should be paid to the following aspects:1) Use RNase free plastic products and gun heads to avoid cross contamination.2) Glassware should be dry baked at a high temperature of 180 ℃ for 4 hours before use, while plastic containers can be soaked in 0.5 M NaOH for 10 minutes, thoroughly rinsed with water, and then sterilized under high pressure.3) Prepare the solution using water without RNase.4) Operators should wear disposable masks and gloves, and change gloves frequently during the experiment.2. The extracted samples should avoid repeated freeze-thaw cycles, otherwise it will affect the quantity and quality of RNA extraction.3. Before use, please check if there is any crystallization or precipitation in the Buffer RL. It can be heated at 56 ℃ and re solved. Please add Buffer RL before use β- Mercaptoethanol, with a final concentration of 1%. Add 10 to 1ml Buffer RL µ L β- Mercaptoethanol. join β- The buffer RL room temperature of mercaptoethanol can be stored for one month.4. Before the first use, anhydrous ethanol should be added to Buffer RW2 according to the instructions on the reagent bottle label.5. All centrifugation steps should be carried out at room temperature unless otherwise specified, and all operation steps should be carried out quickly.6. If downstream experiments are highly sensitive to DNA, it is recommended to treat RNA with DNase I that does not contain RNase.Operation steps1. Sample processing1a organization: Grind the organization in liquid nitrogen. Add 600 to every 20-30 mg of tissue µ L Buffer RL (check if it is added before use) β- Mercaptoethanol), tissue sample less than 20 mg plus 350 µ Buffer RL. The sample volume shall not exceed one tenth of the buffer RL volume.1b Single layer culture of cells: The cells are directly lysed or processed into cell suspensions in a culture bottle, centrifuged to obtain cell precipitates, and the supernatant is discarded. 600 is added every 6-10 cm2 of culture area µ Buffer RL, less than 6 cm2, add 350 µ Blow buffer RL several times to fully crack it.1c cell suspension: Centrifuge at 12000 rpm (~13400 × g) for 1 minute to discard the supernatant and obtain cell precipitate. Add 600 cells every 5 × 106-1 × 107 cells µ Buffer RL, less than 5 × 106 cells added to 350 µ Blow buffer RL several times to fully crack it.Attention:1) Try to eliminate the cell culture medium as much as possible, as it may inhibit cell lysis and affect RNA production.2) Try to fully suspend and lyse the cells, otherwise it will affect RNA production.2. After the sample is fully lysed, it should be left at room temperature for 5 minutes to completely separate the protein nucleic acid complex.3. Centrifuge at 2000rpm for 2-5 minutes, take the supernatant and proceed to the next step.4. Add 1 volume (600) µ L or 350 µ l) Mix 70% ethanol (prepared without RNase water) well.Attention: Adding ethanol may cause precipitation and will not affect subsequent experiments.5. Add all the solution obtained in step 4 to the Spin Columns RM that has been loaded into the collection tube. If it is not possible to add all the solution to the adsorption column at once, please transfer it in two batches, centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube. Attention: The maximum loading capacity of the adsorption column is 100 µ g, do not overload, otherwise it will affect the yield and purity of RNA.6. Add 700 to the adsorption column µ Centrifuge at 12000 rpm for 1 minute, discard the waste liquid from the collection tube, and place the adsorption column in the collection tube.Optional steps: If conducting RNA experiments that are highly sensitive to trace amounts of DNA, replace step 6 with the following steps.1) Add 350 to the adsorption column µ L Buffer RW1, centrifuge at 12000 rpm for 15 seconds, discard the waste liquid, and place the adsorption column back into the recovery manifold.2) Preparation of DNase I mixture: Take 52 µ Add 8 RNase Free Water to it µ 10 x Reaction Buffer and 20 µ DNase I (1 U/ µ l) Mix well and prepare to a final volume of 80 µ The reaction solution of L.Attention: The above system is configured according to our company's DNase I reaction system. Please refer to the corresponding manual for other company products.3) Add 80 µ l of the prepared DNase I reaction solution directly to the adsorption column and incubate at 20-30 ℃ for 15 minutes.4) Add 350 to the adsorption column µ L Buffer RW1, centrifuge at 12000 rpm for 15 seconds, discard the waste liquid, and place the adsorption column back into the recovery manifold.7. Add 500 to the adsorption column µ Buffer RW2 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube.8. Repeat step 7. 9. Centrifuge at 12000 rpm for 2 minutes and discard the waste liquid from the collection tube. Place the adsorption column at room temperature for a few minutes to thoroughly air dry.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).10. Place the adsorption column in a new RNase free centrifuge tube, and add 30-50 to the middle of the adsorption column in the air µ Place RNase Free Water at room temperature for 1 minute, centrifuge at 12000 rpm for 1 minute, collect RNA solution, and store RNA at -70 ℃ to prevent degradation.Attention:1) The volume of RNase Free Water should not be less than 30 µ l. Small volume affects the recovery rate.2) If you want to increase RNA production, you can use 30-50 µ Repeat step 10 for the new RNase Free Water.3) If you want to increase the RNA concentration, you can add the obtained solution back to the adsorption column and repeat step 10... 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 |