| Description | Product introduction：Dualucif The firefly & Renilla assay kit (dual luciferase reporter assay kit) provides an effective means to detect the expression of genes. In DLR detection, the activities of firefly luciferase and Renilla luciferase can be detected in a single sample in turn. FirstProduct introduction：Dualucif The firefly & Renilla assay kit (dual luciferase reporter assay kit) provides an effective means to detect the expression of genes. In DLR detection, the activities of firefly luciferase and Renilla luciferase can be detected in a single sample in turn. First, luciferin was used as substrate to detect the activity of firefly luciferase, then substances inhibiting the catalysis of firefly luciferase were added, and coelenterazine was added to detect the activity of Renilla luciferase to achieve dual luciferase reporter gene detection. The bioluminescence system of luciferase and its substrate can detect gene expression very sensitively and efficiently. Usually, the transcriptional regulatory element or 5'promoter region of the gene of interest is cloned upstream of luciferase, or the 3'-utr region is cloned downstream of luciferase to construct a reporter gene plasmid, and then transfect the cells. After the cells are treated with appropriate drugs, the cells are lysed, and the transcriptional regulation effect of drug treatment on the target gene is judged by detecting the luciferase activity. Renilla luciferase is more often used as an internal reference for detecting transfection efficiency to eliminate the difference in cell number and transfection efficiency. Firefly luciferase is a protein with a molecular weight of about 61 kDa. 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. Renilla luciferase is a protein with a molecular weight of about 36 kDa. In the presence of oxygen, it can catalyze the oxidation of coelenteramide to coelenteramide, and also produce light signals in the process of coelenteramide oxidation. The optical signal of this kit can be measured by chemiluminescence instrument, microplate reader or liquid scintillation tester. The kit has the characteristics of rapid detection, high sensitivity, wide detection range and no interference of cell endogenous activity.Instruction：1.Cell lysis ( 1 ) Remove the medium and gently wash twice with PBS ( adherent cells can be operated directly, suspension cells need to be centrifuged to collect cells ). Add 1 × Lysis Buffer ( diluted component A with sterile water at 4 : 1 ) according to the following scheme, and then place the culture plate on a micro-oscillator at room temperature for 15 min to fully lyse the cells. Note : The pyrolysis products can be stored at room temperature for 6 h, and can be stored at − 70 °C for a long time ( the pyrolysis products cannot be repeatedly frozen and thawed ). ( 2 ) The pyrolysis products were centrifuged at 10000-15000 rpm for 3-5 min. After centrifugation, the supernatant was transferred into a new EP tube for subsequent detection. Note : Cells can be detected immediately after lysis, or frozen, and re-detected when needed. The frozen samples need to be thawed to room temperature for detection. 2. Preparation of working fluid ( 1 ) Restore all components to room temperature. ( 2 ) Dilute component C with component B to 0.2 mg / mL firefly luciferase working solution. Note : The firefly luciferase working solution cannot be repeatedly frozen and thawed. If the amount of a single experiment is small, it is recommended to be subpackaged into small specifications according to a single amount of use. ( 3 ) The E component was diluted into the renilla luciferase working solution with the D component, and the dilution method was 1 µL E component was added to the 49 µL D component. Note : Renilla luciferase working solution needs to be prepared now. 3.chemiluminescence value detection ( 1 ) According to the operation instructions of the instrument, the instrument with chemiluminescence detection function was opened, such as multifunctional microplate reader. The parameters were set, the determination time was 10 s, and the determination interval was 2 s. ( 2 ) each sample determination, take the sample 20-100 µL ( if the sample volume is enough, please add 100 µL ; if the sample amount is insufficient, the amount can be appropriately reduced, but the amount of detection holes needs to be consistent ). 1 × Lysis Buffer was blank control. ( 3 ) 100 µL firefly luciferase working solution was added to determine the RLU ( relative light unit ) value ( it is recommended that the microplate reader set up the Shaking mixing function ). Note : Since the luminescence is instantaneous, it is recommended to detect immediately after adding the firefly luciferase working solution. ( 4 ) 100 µL renilla luciferase working solution was added to determine the RLU ( relative light unit ) value ( Shaking mixing function is recommended for microplate reader ). ( 5 ) In the case of renilla luciferase as an internal reference, the RLU value measured by firefly luciferase was divided by the RLU value measured by renilla luciferase. According to the obtained ratio, the activation degree of the target reporter gene between different samples was compared. If firefly luciferase is used as an internal reference, similar calculations can also be performed.Component：Recommendation：It is recommended to use component B in advance to prepare 2 mg / mL storage solution, component B, component D and component C prepared as storage solution, and to carry out small batch packing according to the experimental requirements. All test working fluids are recommended to be used now to avoid repeated freezing and thawing.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. in order to obtain the best determination effect, when using a single tube chemiluminescence instrument for determination, the time from the mixing of sample and determination reagent to the pre determination should be controlled as much as possible; When using a multi-functional fluorescent microplate reader with chemiluminescence detection function, it is advisable to add all samples first, and then uniformly add firefly luciferase detection reagent. 3. the strongest wavelength of firefly luciferase catalyzed bioluminescence is 560 nm, and the strongest wavelength of Renilla luciferase catalyzed bioluminescence is 480 nm. 4. to prevent interference between holes, it is recommended to use white opaque orifice plate. 5. due to the influence of temperature on enzyme reaction, the sample and reagent should be measured after reaching room temperature. 6. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Study on gene expression regulation and promoter... Read More | When apoptosis occurs, some DNA endonucleases will be activated. These endonucleases will cut off genomic DNA between nucleosomes and produce 180 bp-200 BP DNA fragments, which appear as a specific ladder pattern in agarose gel electrophoresis. When double strand or single strand breaks occur in When apoptosis occurs, some DNA endonucleases will be activated. These endonucleases will cut off genomic DNA between nucleosomes and produce 180 bp-200 BP DNA fragments, which appear as a specific ladder pattern in agarose gel electrophoresis. When double strand or single strand breaks occur in genomic DNA, a large number of sticky 3'-oh ends will be generated, which can interact with YF under the catalysis of deoxyribonucleotide terminal transferase (TDT) ®/ CY dUTP binding can directly detect apoptotic cells by fluorescence microscopy or flow cytometry. This kind of method is called terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Because normal or proliferating cells have almost no DNA breaks, there is no 3'-oh formation and they can rarely be stained. TUNEL method can stain intact single apoptotic nuclei or apoptotic bodies in situ, can accurately reflect the typical biochemical and morphological characteristics of apoptosis, and can detect a very small number of apoptotic cells, so it is widely used in the study of apoptosis. This kit has a wide range of applications and can be used to detect apoptosis in frozen or paraffin sections, as well as cultured adherent cells or suspended cells. It can selectively detect apoptotic cells, but not necrotic cells or cells with DNA strand breaks caused by irradiation and drug treatment. This kit detects cell apoptosis with a short time-consuming, one-step staining reaction and can be detected after washing.Composition: Composition 20T 50T A. aladdin®640 TUNEL Reaction Buffer 1 mL 2 ×1.25 mL B. TdT Enzyme 20 µL 50 µL C. Proteinase K (2 mg/mL) 40 µL 100 µL D. DNase I (2 U/µL) 5 µL 13 µL E. 10 ×DNase I Buffer 100 µL 260 µL Product parameters：642/662 nm； Instruction： Experimental materials (self provided)PBS buffer (1 x, pH~7.4). 0.2% Triton X -100 (PBS formulation). 0.1% Triton X -100 (PBS formulation, containing 5 mg/mLBSA)4% paraformaldehyde (prepared with PBS)Immunohistochemical penDewaxing solvent (paraffin section sample)Related reagents for paraffin section processingAnti fluorescence quenching and sealing agent. ddH2Oexperimental design. A. Positive control:Prepare positive control slides using DNaseI treatment. DNaseI can digest single or double stranded DNA and expose the 3 '- OH end, artificially causing cell apoptosis. One experiment per time is sufficient. (To verify if there are any issues with the experimental operation and reagent kit)B. Negative control:Use TUNEL Reaction Buffer without TdT Enzyme and replace TdT Enzyme with ddH2O. (Mainly to exclude non-specific staining caused by cell apoptosis, operational processes, and other reasons; and to adjust the exposure intensity of the shooting.)C. Experimental processing group.The experimental group operated normally according to the instructions.D. Experimental control group.The experimental group operated normally according to the instructions.Experimental steps1. Sample preparation:(1) For adherent cells or cell smearsa. Clean once with PBS.Note: If you are concerned that the cells on the cell smear may not adhere firmly, you can dry the sample to make the cells adhere more firmly.b. Fixation: Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and fix at 4 ℃ for 30 minutes. Clean twice with PBS.c. Translucency: Add an appropriate amount of 0.2% Triton X -100 (prepared with PBS) and let it penetrate at room temperature for 20 minutes. Clean twice with PBS.d. Step 2: TUNEL reaction.(2) For suspended cells or cell suspensionsa. Collect cells (3-5 x 106 cells), centrifuge at 1000 rpm for 5 minutes, and wash twice with PBS.b. Fixation: Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and resuspend the cells thoroughly. Fix at 4 ℃ for 30 minutes. Centrifuge at 2000 rpm for 5 minutes and clean twice with PBS.c. Translucency: Add an appropriate amount of 0.2% Triton X -100 (prepared with PBS) and let it penetrate at room temperature for 20 minutes. Centrifuge at 2000 rpm for 5 minutes and clean twice with PBS.d. Step 2: TUNEL reaction.(3) Paraffin tissue sectioninga. Dewaxing and hydration: Place the sliced samples sequentially in xylene I (10 min) → xylene II (10 min) → 100% ethanol I (5 min) → 100% ethanol II (5 min) → 95% ethanol (5 min) → 90% ethanol (5 min) → 80% ethanol (5 min) → 70% ethanol (5 min) → ddH2O rinse for 5 min, rinse twice.Note: Xylene is toxic and volatile. Please perform this operation in a fume hood.b. Use filter paper to dry the liquid around the sliced sample, and circle the sample contour with an immunohistochemical pen for downstream transparency and labeling.Note: If it is found that the contour circle of immunohistochemistry strokes is damaged in subsequent experimental operations, it needs to be redrawn in a timely manner.c. Transparency: Dilute 2 mg/mL of ProteinaseK solution with PBS in a ratio of 1:100 to a final concentration of 20 µ g/mL. Add 100 µ L dropwise to each sample to cover all sample areas. Incubate at 20-37 ℃ for 20 minutes.Note: Protein K can penetrate the cell membrane and nuclear membrane, allowing subsequent staining reagents to fully enter the nucleus for reaction and improve labeling efficiency. An excessively long incubation time increases the risk of tissue slices falling off the carrier film during subsequent washing steps, while a too short incubation time may result in insufficient permeability treatment and affect labeling efficiency. To obtain better results, the concentration, incubation time, and temperature of Protein K need to be optimized according to different types of tissue samples.d. Wash the slices twice with PBS, each time for 5 minutes. Use filter paper to remove excess liquid, and place the processed sample in a wet box to keep it moist.Note: Protein K must be washed thoroughly in this step, otherwise it will seriously interfere with subsequent labeling reactions.e. Step 2: TUNEL reaction.(4) Frozen tissue sectionsa. Fixation: Take out frozen sections and warm them back to room temperature. Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and fix at room temperature for 30 minutes. Wash twice with PBS for 10 minutes each time.Note: If you are concerned that formaldehyde cleaning may not be clean enough, it may affect the final dyeing effect. After formaldehyde fixation is completed, an appropriate amount of 2 mg/mL glycine can be added and washed for 10 minutes to neutralize the residual fixing solution, and then PBS cleaning can be carried out.b. Use filter paper to dry the liquid around the sliced sample, and circle the sample contour with an immunohistochemical pen for downstream transparency and labeling.Note: If it is found that the contour circle of immunohistochemistry strokes is damaged in subsequent experimental operations, it needs to be redrawn in a timely manner.c. Transparency: Dilute 2 mg/mL of ProteinaseK solution with PBS in a ratio of 1:100 to a final concentration of 20 µ g/mL. Add 100 µ L dropwise to each sample to cover all sample areas. Incubate at 20-37 ℃ for 20 minutes.Note: Protein K can penetrate the cell membrane and nuclear membrane, allowing subsequent staining reagents to fully enter the nucleus for reaction and improve labeling efficiency. An excessively long incubation time increases the risk of tissue slices falling off the carrier film during subsequent washing steps, while a too short incubation time may result in insufficient permeability treatment and affect labeling efficiency. To obtain better results, the concentration, incubation time, and temperature of Protein K need to be optimized according to different types of tissue samples.d. Wash the slices twice with PBS, each time for 5 minutes. Use filter paper to remove excess liquid, and place the processed sample in a wet box to keep it moist.Note: Protein K must be washed thoroughly in this step, otherwise it will seriously interfere with subsequent labeling reactions.e. Step 2: TUNEL reaction.(5) Positive treatment (only the positive control is subjected to this step, and other samples are directly subjected to the TUNEL reaction step)a. Dilute 10 x DNase I Buffer with ddH2O in a ratio of 1:10 to 1 x DNase I Buffer for later use.b. Drip 100 µ L of 1xDNase I Buffer onto the processed sample, covering all sample areas, and equilibrate at room temperature for 5 minutes.c. Dilute DNase I (2 U) with 1 x DNase I Buffer at a ratio of 1:100/ µ L) A working solution with a final concentration of 20 U/mL.d. Discard the buffer and add 100 µ Incubate DNase I working solution with a concentration of 20 U/mL at room temperature for 10 minutes.e. Discard DNase I working solution and clean twice with PBS.f. Step 2: TUNEL reaction.2. TUNEL reaction(1) Prepare TUNEL reaction solution (ready to use): / 1 sample 5 sample 10 sample TdT enzyme 1 µL 5 µL 10 µL YF®488/555/594/640 TUNEL Reaction Buffer 49 µL 245 µL 490 µL TUNEL Total volume of reaction solution 50 µL 250 µL 500 µL (2) For adherent cells, cell smears, or tissue sectionsa. Add 50 to each sample µ L TUNEL reaction solution, evenly cover the sample with the reaction solution. The appropriate time for dark incubation at 37 ℃ (recommended staining time for cells is 30 minutes to 1 hour, and tissue staining time is 2 hours).Note: 50 µ L TUNEL reaction solution is suitable for smear, slicing, or 96 well plates (other different well plates can adjust the volume of TUNEL reaction solution appropriately to cover cells). If the sample to be tested is a smear, slice, or in a 24 well plate, 12 well plate, or 6 well plate, anti evaporation film can be used, or self sealing bags or other appropriate materials can be used to cut circular plastic sheets slightly smaller than the holes. After adding TUNEL reaction solution dropwise, cover the sample to prevent the evaporation of TUNEL reaction solution and make the TUNEL reaction solution evenly cover the sample.b. Discard the TUNEL reaction solution, wash twice with PBS, and then wash three times with 0.1% Triton X -100 (PBS preparation, containing 5 mg/mL BSA) for 5 minutes each time. This way, free unreacted markers can be removed cleanly.c. (Optional) Add an appropriate concentration of 5 to each sample µ DAPI staining solution with a concentration of g/mL, incubated at room temperature in dark for 5 minutes. After staining, discard DAPI staining solution and wash twice with PBS for 5 minutes each time.d. (Optional) Slice sealing: Add 50 drops to each sample µ L anti fluorescence quenching sealing agent (anti fluorescence quenching sealing agent may not be suitable for certain dyes, it is recommended to conduct pre experimental testing for compatibility before the experiment), cover the cover glass, gently tap the cover glass with the blunt end of tweezers to remove bubbles and ensure complete sealing.e. Use filter paper to remove excess liquid and add 100 to the sample area µ Keep the sample moist with PBS and immediately observe under a fluorescence microscope.(3) For suspended cells or cell suspensionsa. Add 50 to each sample tube µ Gently resuspend cells in LTUNEL reaction solution and incubate at 37 ℃ in the dark for 30-1 hour. Gently resuspend cells with a micropipette every 15 minutes.b. Centrifuge at 2000 rpm for 5 minutes, discard TUNEL reaction solution, and wash twice with 0.1% Triton X -100 (PBS preparation, containing 5 mg/mLBSA) for 5 minutes each time. This way, free unreacted markers can be removed cleanly.c. Add 100 to each sample tube µ L concentration is 5 µ DAPI staining solution with a concentration of g/mL, incubated at room temperature in dark for 5 minutes.d. Join 400 µ L PBS resuspended cells and immediately detected with a flow cytometer or observed under a fluorescence microscope after smearing.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. when the staining background is heavy or non-specific staining is obvious, the staining time can be appropriately reduced. 3. it is recommended to add negative control and positive control groups during the experiment. 4. please wear mask and gloves when using component A. if it contacts the skin, please wash it with plenty of water immediately. 5. fluorescent dyes have quenching problems. Please try to avoid light to slow down fluorescence quenching. 6. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Late apoptosis detection, TUNEL Kit... Read More | Lipid peroxidation is the degradation of lipids that occurs as a result of oxidative damage and is a useful marker for oxidative stress. Polyunsaturated lipids are susceptible to an oxidative attack, typically by reactive oxygen species, resulting in a well-defined chain reaction with the productionLipid peroxidation is the degradation of lipids that occurs as a result of oxidative damage and is a useful marker for oxidative stress. Polyunsaturated lipids are susceptible to an oxidative attack, typically by reactive oxygen species, resulting in a well-defined chain reaction with the production of end products such as malondialdehyde (MDA). Lipid peroxidation may contribute to the pathology of many diseases including atherosclerosis, diabetes, and Alzheimer′s.Lipid peroxidation (MDA) assay kit has been used to determine the levels of malondialdehyde (MDA).Suitability: Suitable for the measurement of malondialdehyde (MDA) in a variety of samples including tissue, cells and plasmaPrinciple: In this kit, lipid peroxidation is determined by the reaction of MDA with thiobarbituric acid (TBA) to form a colorimetric (532 nm)/fluorometric (λex= 532/λem= 553 nm) product, proportional to the MDA present... Read More | N665925 Component 1 mL 5 mL Storage N665925A 2×SYBR qPCR Master Mix 1 1 mL 5 mL -20℃. Avoid freeze/ Thaw cycle. N665925B qPCR Primer Mix 1 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925C DNA Standard I 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925 Component 1 mL 5 mL Storage N665925A 2×SYBR qPCR Master Mix 1 1 mL 5 mL -20℃. Avoid freeze/ Thaw cycle. N665925B qPCR Primer Mix 1 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925C DNA Standard I 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925D DNA Standard II 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925E DNA Standard III 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925F DNA Standard IV 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925G DNA Standard V 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665925H 50×High ROX 40 µL 200 µL -20℃. Avoid freeze/ Thaw cycle.Product IntroductionThis product is a real-time fluorescence quantitative PCR of the products after NGS library construction using a dye method (SYBR Green I).(qPCR). The kit provides the reaction mixes, DNA primer mixtures, standards and sample dilutions required for the qPCR process, making the reagent system complete and easy to use. The fluorescent dye SYBR Green I contained in the reaction mixture can bind to all double-stranded DNA; the GoldStar Taq DNA Polymerase used is a chemically modified new high-efficiency hot-start polymerase, and the activation of the enzyme needs to be incubated at 95℃ for 10 minutes. the product has high specificity, high amplification efficiency, and is able to quickly and accurately quantify the concentration of the constructed libraries. The product is highly specific and efficient in amplification, and can quickly and accurately quantify the concentration of the constructed library.ROX dye is used to correct the fluorescence signal error generated between wells of a quantitative PCR instrument, and is generally used in Real Time PCR amplifiers from ABI, Stratagene, and other companies. The excitation optics vary from instrument to instrument, so the concentration of ROX dye must be matched to the corresponding fluorescence quantitative PCR instrument.Instruments that do not require ROX calibration: Roche LightCycler 480, Roche LightCyler 96, Bio-rad iCyler iQ, iQ5, CFX96, etc.Instruments requiring Low ROX calibration: ABI Prism7500/7500 Fast, QuantStudio®3 System, QuantStudio®5 System, QuantStudio®6 Flex System, QuantStudio®7 Flex System, ViiA 7 System, Stratagene Mx3000/Mx3005P, Corbett Rotor Gene 3000, and others.Instruments requiring High ROX calibration: ABI Prism7000/7300/7700/7900, Eppendorf, ABI Step One/Step One Plus, etc.Note: High Rox and Low Rox are formulated as described in Use 2.Scope of applicationThis product is designed for absolute quantification of the concentration of Ion torrent platform second generation sequencing libraries. The end of the library contains Ion torrent P5 and P7 microarray binding sequences, the length of which does not exceed 1kb, and the concentration is not less than 0.005pM can be used to perform quantitative experiments with this product. The qPCR Primer Mix provided in the kit contains the following two primer sequences:Primer 1:5'-CCA TCT CAT CCC TGC GTG TC - 3' Primer 2: 5'-CCT CTC TAT GGG CAG TCG GTG AT-3'The primer sequence can be used in advance to confirm whether the library can be amplified by that primer pair.Usage1. Amplification template preparationThe library samples to be detected were diluted with TE (10 mM Tris-Cl, pH 8.0, 1 mM EDTA), and the concentration after dilution was as close as possible to the range of 0.05-50 pM. 4°C on ice was set aside.2. qPCR reaction system preparationThe desired cryopreservation reagent is pre-melted completely and mixed by inverting several times before preparation, then centrifuged briefly and set aside.The base reaction system for 20 µl was as follows:Reagent20 µl Reaction system2×SYBR qPCR MasterMix10 µlqPCR Primer Mix 10.8 µlTemplate4 µlddH₂O5.2 µlDescription: High Rox model: add 1 µl High Rox per 50 µl of reaction system;Low Rox model: 1 µl High Rox per 500 µl of reaction system.Prepare a sufficient amount of reaction system mixture according to the need, mix well and add to the reaction wells in a volume of 16 µl per well, add the same volume of TE to the blank control, and then add the prepared standards and diluted samples to the corresponding reaction wells in a volume of 4 µl/well. It is recommended to use 20 µl reaction system, if you need to carry out a smaller system reaction, the system components can be reduced in equal proportion.3. qPCR reaction program1) Please use 60-64℃ as a reference for setting range of annealing temperature, and increase the annealing temperature when non-specific reaction occurs.2) If the average length of the library is greater than 700bp, the annealing/extension time should be increased appropriately.data analysis1. Standard curve productionThe standard curve was plotted using Ct values in the valid range. The standard curve correlation coefficient R2 should not be less than 0.99 and the slope should lie between -3.1 and -3.6. If the standard curve parameters are not reasonable, it is recommended to repeat the experiment.DNA Standard NameDNA Standard ConcentrationDNA Standard I50 pMDNA Standard II5 pMDNA Standard III0.5 pMDNA Standard IV0.05 pMDNA Standard V0.005 pM2. Library concentration calculationThe difference in Ct between the three replicate wells of the experiment should be no more than 0.2, otherwise the invalid data should be deleted or the experiment should be repeated. Do not use the Ct outside the valid Ct range of the standard curve to calculate the concentration of the diluted libraries. Please refer to the data processing Excel of this product for the specific library concentration calculation method.matters needing attention1. Before testing, these instructions should be read in detail. It should be operated by personnel with professional experience or qualified by training.2. For use, please mix gently by turning up and down, avoid foaming as much as possible, and use it after centrifugation for a short period of time.3. Avoid repeated freezing and thawing of the product, repeated freezing and thawing may degrade the performance of the product.4. When preparing the reaction solution, please use new or non-contaminated tips and centrifuge tubes to prevent contamination as much as possible... Read More | Inquire |