| Description | Glutathione is a tripeptide containing a γ-amide bond and a sulfhydryl group, composed of glutamate, cysteine, and glycine. It is widely found in animal and plant tissues and microorganisms. In living organisms, it helps maintain normal immune system function and has antioxidant and Glutathione is a tripeptide containing a γ-amide bond and a sulfhydryl group, composed of glutamate, cysteine, and glycine. It is widely found in animal and plant tissues and microorganisms. In living organisms, it helps maintain normal immune system function and has antioxidant and detoxifying effects. Glutathione exists in two forms: reduced (GSH) and oxidized (GSSG). GSSG, also known as glutathione disulfide, is formed by the oxidation of two glutathione molecules. GSSG can be reduced back to GSH by glutathione reductase; therefore, it exists primarily in the reduced form in organisms. The ratio of reduced to oxidized glutathione (GSH/GSSG) serves as a key dynamic indicator for assessing the cellular redox state. Detection Principle: Endogenous GSH in the sample is masked by 2-vinylpyridine. Under the catalysis of glutathione reductase (GR), GSSG is reduced to GSH. The generated GSH then reacts with 5,5'-Dithiobis-(2-nitrobenzoic acid) (DTNB) to produce yellow-colored 5-thio-2-nitrobenzoic acid (TNB), which has a characteristic absorption peak at 412 nm. The GSSG content is quantified by measuring the change in absorbance. Detection Range: 1-20 µM Sensitivity: 1 µM Applicable Samples: Animal/plant tissues, blood cells, cells, bacteria, serum (plasma).O1492795Component96TStorageO1492795AExtraction Buffer70 mL×22-8℃O1492795BInhibitor210 µL-20℃. Store in the dark.O1492795CAssay Buffer20 mL2-8℃O1492795DGR14 µL2-8℃. Store in the dark.O1492795EGR Cofactor2 EA-20℃. Store in the dark.O1492795FChromogen2 EA2-8℃. Store in the dark.O1492795GStandard1 EA2-8℃. Store in the dark.User-Provided Instruments and ReagentsTypeNameNotesInstrumentMicroplate ReaderCapable of measuring absorbance at 412 nm.Consumables96-well MicroplateStandard transparent plate.ReagentsPBS / Deionized WaterFor washing samples / Preparing reagents.OthersHomogenizer (for tissue samples), water bath, ice bucket, low-temperature centrifuge, adjustable pipettes and tipsUsing a multichannel pipette for large-scale detection can improve efficiency.Experimental Procedure1. Reagent PreparationReagent NameReagent PreparationPrecautionsExtraction BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C.Diluted Extraction BufferAdd 500 µL Extraction Buffer to 4.5 mL deionized water.Obtained by 10-fold dilution of Extraction Buffer.InhibitorReady-to-use; equilibrate to room temperature before use.Store at -20°C protected from light. Toxic and irritant; recommended to handle in a fume hood.Assay BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C.GR DilutionBefore use, prepare by adding 1 µL GR to 20 µL deionized water per sample.Prepare freshly before use.GR Cofactor DilutionBefore use, add 1.5 mL deionized water to each vial; equilibrate to room temperature protected from light.After dissolution, store at -20°C protected from light for up to 1 month.Chromogen DilutionBefore use, add 1.5 mL deionized water to each vial; equilibrate to room temperature protected from light.After dissolution, store at 4°C protected from light for up to 1 month.GSSG StandardDissolve in 1 mL of Diluted Extraction Buffer.20 mM; After dissolution, aliquot and store at -20°C protected from light for up to 1 month.2. Standard PreparationTake 100 µL of the 20 mM GSSG standard and dilute with 900 µL Diluted Extraction Buffer to obtain a 2 mM GSSG standard solution.Take 10 µL of the 2 mM GSSG standard and dilute with 990 µL Diluted Extraction Buffer to obtain a 20 µM GSSG standard solution.Further dilute the standard as shown in the table below. A standard curve must be prepared for each experiment. Diluted standard solutions are unstable and must be used within 4 hours.Standard Working Solution20µM Standard (µL)Diluted Extraction Buffer (µL)Concentration (µM)110002028020163604012440608520804610902759513. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for up to 10 days. Because the Extraction Buffer contains a protein precipitant, the supernatant cannot be used for protein concentration determination. If protein content needs to be measured, prepare another identical sample using deionized water instead of Extraction Buffer.3.1 Animal/Plant Tissue Samples:Use fresh tissue samples whenever possible. Weigh 0.1 g of tissue, add 1 mL of pre-cooled Extraction Buffer, and homogenize quickly on ice (pre-cool the homogenizer on ice). Centrifuge the homogenate at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.2 Serum/Plasma Samples:Use fresh serum (plasma) whenever possible. Centrifuge the collected serum (plasma) at 600 g, 4°C for 10 min. Within 30 minutes, aspirate the supernatant into another tube. Add an equal volume of Extraction Buffer, mix, then centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.3 Cell or Bacterial Samples:Use fresh cells (bacteria) whenever possible; avoid using frozen cells (bacteria). Collect 5×10⁶ cells (bacteria). Wash twice with 1 mL of pre-cooled PBS (resuspend in PBS, centrifuge at 600 g, 4°C for 10 min). Add 3 times the volume of Extraction Buffer relative to the cell (bacterial) pellet to resuspend the cells (bacteria). Disrupt by ultrasound on ice (power 20% or 200 W, ultrasonicate for 3 s, interval 7 s, repeat 30 times). Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.Note: Cells can also be extracted using a freeze-thaw method (not suitable for bacteria): Resuspend cells and subject to 2-3 rapid freeze-thaw cycles (freeze in liquid nitrogen, thaw in a 37°C water bath). Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.4. Assay Steps4.1 Microplate Reader Preparation: Preheat for at least 30 minutes, set wavelength to 412 nm.4.2 Assay System Setup (Step 1 - Pre-treatment): Perform the following operations in 1.5 mL EP tubes. This step must be done in EP tubes. Do not add Inhibitor directly to the 96-well plate as it may corrode the plate. Inhibitor is toxic and irritant; recommended to handle in a fume hood.ReagentBlank Tube (µL)Standard Tube (µL)Test Tube (µL)Sample003Deionized Water30027Standard0300Inhibitor1.51.51.54.3 Mix well and incubate at 37°C for 30 minutes. This becomes the "Mixture".4.4 Assay System Setup (Step 2 - Reaction): Perform the following operations in a 96-well plate.ReagentBlank Well (µL)Standard Well (µL)Test Well (µL)Mixture212121Assay Buffer140140140GR Dilution222GR Cofactor Dilution202020Chromogen Dilution2020204.5 Absorbance Measurement: Mix thoroughly after addition. Read the absorbance at 412 nm (A1), recorded as A1 blank, A1 standard, and A1 test. Then incubate at 37°C protected from light for 10 minutes. Quickly read the absorbance at 412 nm again (A2), recorded as A2 blank, A2 standard, and A2 test. 5. Result Calculation The following provides both the derived formula and the simplified calculation formula, which are completely equivalent. 5.1 Data Processing Calculate ΔA = A2 - A1 for each. Then calculate ΔΔA standard = ΔA standard - ΔA blank And ΔΔA test = ΔA test - ΔA blank 5.2 Standard Curve Plotting 5.2 Standard Curve Plotting Plot the standard curve with standard concentration as the y-axis and ΔΔA standard as the x-axis. Substitute ΔΔA test into the equation to obtain the y value (µM). 5.3 Sample GSSG Content Calculation (1) Based on sample mass: GSSG (nmol/g) = y × V standard ÷ V sample × V extract ÷ W × n = 10 × y ÷ W × n (2) Based on cell or bacterial count: GSSG (nmol/10⁴) = y × V standard ÷ V sample × V extract ÷ 500 × n = 0.02 × y × V extract × n (3) Based on liquid volume: GSSG (nmol/mL) = y × V standard ÷ V sample × 2 × n = 20 × y × n (4) Based on protein concentration: GSSG (nmol/mg prot) = y × V standard ÷ V sample ÷ Cpr × n = 10 × y ÷ Cpr × n Parameter Description: 1 µM = 1 nmol/mL; V standard : Volume of standard added, 30 µL; V sample : Volume of sample added, 3 µL; V extract : Volume of Extraction Buffer added, 1 mL (for cells/bacteria, use the actual volume used); W: Sample mass, g; n: Sample dilution factor; Cpr: Sample protein concentration, mg/mL; 500: Cell or bacterial count, in units of 10⁴; 2: Dilution factor for liquid samples (added equal volume of Extraction Buffer).6. Result PresentationTypical Standard Curve: y = 8.0042x + 0.212, R² = 0.9997Example-1: 0.1 g of rat liver tissue was processed and assayed according to the procedure using a 96-well plate. Measured: ΔA test = A2 test - A1 test = 0.386 - 0.120 = 0.266 ΔA blank = A2 blank - A1 blank = 0.132 - 0.097 = 0.035 ΔΔA test = ΔA test - ΔA blank = 0.266 - 0.035 = 0.231 Substituting ΔΔA test into the standard curve equation gives y = 2.061 µM. Calculated based on sample mass: GSSG (nmol/g) = y × V standard ÷ V sample × V extract ÷ W × n = 10 × y ÷ W × n = 206.1 nmol/g.Precautions1. It is recommended to perform preliminary experiments using 2-3 samples expected to have significant differences before formal testing.2. The samples extracted with this kit are suitable for the detection of oxidized glutathione (GSSG). Because the extraction buffer contains a protein precipitant, the supernatant cannot be used for protein concentration determination. If protein content needs to be measured, prepare another identical sample using deionized water instead of the extraction buffer. For protein concentration determination, Aladdin BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) are recommended.3. This kit is compatible with spectrophotometer detection. Adjust the preparation volume of detection reagents proportionally according to the spectrophotometer's requirements.4. It is recommended to establish your own standard curve for improved accuracy. If not, you may refer to the typical standard curve formula provided in the results section for calculation.5. Biochemical reagents are generally irritating and biologically toxic. For your safety and health, please wear appropriate personal protective equipment (lab coat, mask, gloves, hair cap, etc.) throughout the experiment and perform experiments in a fume hood or biosafety cabinet.6. This product is for scientific research use only. Not intended for clinical diagnosis.Frequently Asked Questions Q: What should I do if the sample ΔA test is too high or too low? Frequently Asked Questions Q: What should I do if the sample ΔA test is too high or too low? A: If the sample ΔA test is greater than the ΔA standard of the 20 µM standard, the GSSG content in the sample is too high. Dilute the sample appropriately with deionized water (multiply by the dilution factor in the calculation). If the sample ΔA test is less than 0.005, increase the sample amount.Q: Can blood cell samples be detected?A: Yes, blood cell samples can be detected. Centrifuge the collected anticoagulated blood at 600 g, 4°C for 10 min. Discard the upper plasma and wash the pellet 2-3 times with 3 volumes of PBS (resuspend blood cells in PBS, centrifuge at 600 g, 4°C for 10 min). Add an equal volume of Extraction Buffer, mix, and let stand at 4°C for 10 min. Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection... Read More | D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to acidemia and acidosis. The severity of this D-lactic acidosis can be associated with neurotoxic symptoms. Significant D-Lactate accumulations in the body can also be related to impaired metabolism and excretion.D-Lactate Colorimetric Assay kit has been used to determine the stereospecificity of lactate produced.Suitability: Suitable for use with samples of serum, plasma, cells, culture and fermentation media.Principle: In this assay, D-Lactate is specifically oxidized by D-Lactate hydrogenase and generates a proportional colorimetric product measured at 450 nm. The useful concentration range in samples is 0.1-10 mM D-Lactate... Read More | Product Characteristics Effect Diluents, Animal-free are effective buffers free of any animal components. They can be used for the dilution of serum, plasma, blood, stool or urine samples, as well as the dilution of primary and secondary antibodies. Effect Diluents, Animal-free efficiently minimize Product Characteristics Effect Diluents, Animal-free are effective buffers free of any animal components. They can be used for the dilution of serum, plasma, blood, stool or urine samples, as well as the dilution of primary and secondary antibodies. Effect Diluents, Animal-free efficiently minimize matrix effects, cross-reactions and unspecific binding in immunoassays like ELISA, Western blotting, Immunohistochemistry, protein arrays and immuno-PCR.The Effect Diluents, Animal-free are used alternatively to the standard sample or antibody dilution buffers: In ELISA for the dilution of specimen and detection antibodies. In Western Blotting for the dilution of primary and secondary antibodies. In Protein arrays for the dilution of specimen and detection antibodies. In immuno-PCR as a washing buffer.Three versions of the diluent are offered: Low, Medium and High for optimal discrimination between specific and unspecific reaction and for minimizing strong interference effects e.g., by RF (rheumatoid factors), HAMAs (human-a-mouse Abs) or by endogenous components that bind and mask the analyte.Composition & Properties The Effect Diluents, Animal free contain no animal components and are free of phosphates.Working Procedure 1.Mix thoroughly prior to use. 2.Dilution recommendations a.Dilute antibodies according to the instruction of the antibody b.Dilution of the specimen is recommended at 1:2 or higherTips & TricksEffect Diluents must not be considered as blocking buffers. Recommended blocking buffers are: Synthetic Blocking Buffer, ELISA (cat. no. S494401), Synthetic Blocking Buffer, Blotting (cat. no. S494457) and WellChampion (cat. no. W494467) for plate blocking and stabilization (preparation of pre-coated plates). Complex sample matrices, such as serum and plasma, may contain interfering factors that affect the ability of the assay to accurately quantify the target analyte. Strong interferences are often caused by RFs and HAMAs. This matrix effect can cause high background in the negative control or false negatives in the sample measurement. To reduce this effect the samples can be diluted in the Effect Diluents, Animalfree.Handling & Storage Store solution 2-8°C or -15 to -30°C (tolerates freezing and thawing cycles)... Read More | DescriptionTruQuant IQQ is a high-quality quantitation system for making simultaneous accurate biological measurements on several hundred biochemicals in small quantities of biological samples. This is achieved by (1) spiking a complex Internal Standard (WORKFLOW-A) into a biological sample to a) DescriptionTruQuant IQQ is a high-quality quantitation system for making simultaneous accurate biological measurements on several hundred biochemicals in small quantities of biological samples. This is achieved by (1) spiking a complex Internal Standard (WORKFLOW-A) into a biological sample to a) quantify all the biochemicals in the sample relative to their counterparts in the Internal Standard, b) suppression-correct each compound and c) normalize sample to sample variances; and (2) injecting the same well characterized Long-Term Reference Standard (WORKFLOW-B) to create a daily retention time (RT) library of all compounds to be found in the Internal Standard for reproducible ID, and to measure day-to-day (QA/QC) to assure reproducible instrument performance. The system is completely automated using IROA ClusterFinder™software.IROA TruQuant IQQ Workflow Kit contains the materials and tools for the analysis of 90 experimental samples. The kit is intended to be used for mass spectrometry metabolomics applications... Read More | Product introduction：Reporter gene detection is an important tool for analyzing the interaction between potential cis elements (such as promoters, enhancers and silencers) and trans acting factors in the flanking region of structural genes in the field of modern molecular biology. Firefly Product introduction：Reporter gene detection is an important tool for analyzing the interaction between potential cis elements (such as promoters, enhancers and silencers) and trans acting factors in the flanking region of structural genes in the field of modern molecular biology. Firefly luciferase is widely used in gene regulation and drug screening. Firefly luciferase is a protein with a molecular weight of about 61 KD. In the presence of ATP, magnesium ions and oxygen, it can catalyze the production of oxyluciferin from luciferin. In the process of luciferin oxidation, it will produce a light signal. The optical signal of this kit is a kind of instantaneous light, which needs to be detected immediately after adding the working solution. The half-life of optical signal is about 5 min.Instruction：1.Working fluid configuration ( 1 ) Restore all components to room temperature. ( 2 ) The component B ( stock solution ) was fully diluted with component A to prepare a 0.2 mg / mL firefly luciferase working solution, which was vortexed and shaken to ensure full mixing. Note : The firefly luciferase working solution cannot be repeatedly frozen and thawed. If the dosage of a single experiment is small, it is recommended to subpackage according to a single dosage. At room temperature, the activity decreased by about 10 % after the working solution was configured for 3 h, and the activity decreased by about 25 % after 5 h. 2.chemiluminescence value detection ( 1 ) The cell culture plate was taken out from the incubator and incubated at room temperature for 20 min to restore it to room temperature ( 22-25 ° C ). ( 2 ) Add the same volume of firefly luciferase working solution with the medium to the culture plate and mix well. ( 3 ) Incubation at room temperature for 5 min. Note : The incubation time can be adjusted according to cell type and cell number. ( 4 ) The values were read by multifunctional microplate reader or chemiluminescence instrument ( instrument parameters : the determination time was 10 s, the determination interval was 2 s ).Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. the strongest wavelength of bioluminescence catalyzed by firefly luciferase is 560 nm. 3. to prevent interference between holes, it is recommended to use white opaque orifice plate.Recommendation：Component B is recommended to use sterile water in advance to configure 2 mg / mL storage solution, A component and B component configured as storage solution, and small batch packaging according to the experimental requirements. The detection working fluid is recommended to be used now to avoid repeated freezing and thawing. Component：One-Step Firefly Luciferase Assay Buffer；D-Luciferin Scope of application：Mainly used for ADCC detection... Read More |