78 results about "Deamination" patented technology

The invention relates to a low-molecular-weight chondroitin sulfate composition as well as a preparation method and application thereof, and aims to solve the problems that a chondroitin sulfate product obtained by a single degradation mode is limited in function and difficult to synergistically regulate intestinal barriers. The preparation method comprises the following steps: firstly, preparing LMCSO through oxidative degradation; secondly, preparing LMCSH through hydrothermal degradation; and finally, the LMCSD is prepared through deamination degradation. Finally, the obtained LMCSO, LMCSH and LMCSD are compounded according to the weight ratio of 5: 3: 2, and the low-molecular-weight chondroitin sulfate composition LMCSs-C is obtained. The composition LMCSs-C prepared by the invention can synergistically improve the intestinal barrier function through multiple action mechanisms, not only shows an obvious intestinal barrier repair effect in vitro and animal models, but also has good biocompatibility and safety, and shows a wide application prospect in intestinal health maintenance and related disease intervention.

The invention discloses a sulfur-oxidizing bacterium screening and enriching nutrient solution, a sulfur-oxidizing bacterium enriching method and a deodorizing method. The sulfur-oxidizing bacterium screening and enriching nutrient solution comprises 1.0 g.L <-1 > of K2HPO4, 0.5 g.L <-1 > of NaHCO3, 0.05 g.L <-1 > of NH4Cl, 0.225 g.L <-1 > of Na2S. 9H2O and 0.001 g.L <-1 > of trace elements, wherein the trace elements comprise 0.5 g.L <-1 > of EDTA (Ethylene Diamine Tetraacetic Acid), 0.01 g.L <-1 > of (NH4) 6Mo7O24. 4H2O, 0.04 g.L <-1 > of ZnSO4. 7H2O, 0.03 g.L <-1 > of MnCl2. 7H2O, 0.02 g.L <-1 > of CuSO4. 5H2O The deodorization performance of the municipal sewage treatment plant is improved through synchronous desulfurization and deamination of the acidophilic sulfur-oxidizing bacteria, and compared with a traditional deodorization process, the synchronous desulfurization and deamination process can enrich high-abundance sulfur-oxidizing bacteria in a short time and shows higher ammonia gas and hydrogen sulfide removal capacity.

The present invention relates to antisense oligonucleotides (AONs) that can mediate RNA editing by binding to a target RNA nucleic acid molecule, preferably an RNA transcript molecule, in a cell and recruiting an endogenous deaminating enzyme in the cell to deaminate a target adenosine in the target RNA molecule to an inosine. The target RNA molecule is a transcript molecule form the SLC10A1 gene that encodes the Na+ / Taurocholate Co-transporting Polypeptide (NTCP), and the target adenosine is the adenosine in the GAC codon coding for aspartic acid (D) at position 24 of the NTCP protein. The deamination of the adenosine changes the amino acid to a glycine (G). The RNA editing of the adenosine will result in a loss-of-function of the NTCP protein, which will result in lowered uptake of bile acids from the portal circulation into the liver, thereby lowering the risk of suffering from disorders related to bile accumulation in the liver.

The invention discloses a preparation method and application of a metal carrier loaded with deamination tyrosine, the preparation method comprises the following steps: ZrOCl28H2O, TCPP and benzoic acid with a specific ratio and concentration are synthesized into Zr-MOFs with a specific particle size and structure, then the Zr-MOFs react with deamination tyrosine with a certain concentration, and DAT-Zr-MOF is prepared through a two-step method. The prepared DAT (at) Zr-MOF loaded deamination tyrosine is high in content and good in stability, can effectively solve the problem that deamination tyrosine is subjected to enzymolysis and oxidation, and can be used for treating wounds and promoting tissue repair through external application.

The invention belongs to the technical field of synthesis of ester compounds, and particularly relates to a preparation method of 2, 6-dichloro-4-cyanobenzoic acid methyl ester, which comprises the following steps: by taking dimethyl 2-aminoterephthalate as a raw material, sequentially carrying out substitution reaction, deamination reaction, hydrolysis reaction, amidation reaction and dehydration reaction to obtain the 2, 6-dichloro-4-cyanobenzoic acid methyl ester. The 2, 6-dichloro-4-cyanobenzoic acid methyl ester is prepared by the method, and the yield reaches 59.28%. The N-chlorosuccinimide is used as a chlorine source to carry out substitution reaction on the 2-amino dimethyl terephthalate, so that the potential safety hazard caused by the traditional chlorination reagent is avoided, and the tert-butyl nitrite used in the deamination reaction avoids the potential safety hazard caused by the use of strong corrosive sulfuric acid; the amidation reaction is completed in one step by adopting a condensing agent, so that the complicated operation caused by firstly preparing acyl chloride and then carrying out condensation reaction is avoided, and therefore, the preparation method has the characteristics of safe preparation process, environment friendliness, simplicity in operation and the like under the condition of ensuring the product yield and purity.

This utility model discloses a ternary precursor material mother liquor ammonia removal treatment system, including an ammonia removal tower, a falling film evaporator, a dilute ammonia water tank, a condenser, and an ammonia water storage tank. The top of the ammonia removal tower is connected to the shell side of the falling film evaporator section via an ammonia gas outlet pipe, and the bottom of the ammonia removal tower is connected to the gas-liquid separation section via a liquid outlet pipe. The shell side of the falling film evaporator section is connected to the cooling inlet end of the condenser via an ammonia gas outlet pipe, and the cooling outlet end of the condenser is connected to the ammonia water storage tank. A dilute ammonia water inlet pipe and a reflux pipe are connected between the shell side of the falling film evaporator section and the top of the dilute ammonia water tank. A liquid outlet pipe is connected to the gas-liquid separation section. A reflux pipe and a falling film circulation pump are connected between the liquid outlet pipe and the top of the tube side of the falling film evaporator section. A vapor compression unit is provided between the gas-liquid separation section and the ammonia removal tower. This utility model has the advantages of reducing the amount of vapor used in the ammonia removal tower, reducing energy consumption, achieving good ammonia removal effect from the mother liquor, achieving good ammonia water recovery effect, low system operating cost, and stable and reliable operation.

The invention relates to a preparation method of N-alpha-t-butyloxycarboryl-L-lysine (N-alpha-t-butyloxycarboryl). The preparation method of the N-alpha-t-butyloxycarbonyl-L-lysine comprises the following steps: mixing L-lysine hydrochloride with hyperbranched aromatic borate, reacting under the action of a phosphate buffer solution and N, N-dimethylformamide to obtain an intermediate b, mixing the intermediate b with benzyl halide, reacting under the action of alkali and a solvent I to obtain an intermediate c, and reacting under the action of a solvent II to obtain the N-alpha-t-butyloxycarbonyl-L-lysine. The intermediate c, a phosphate buffer solution and N, N-dimethylformamide are mixed and then react to obtain an intermediate d, the intermediate d and di-tert-butyl dicarbonate ester are mixed and then react under the action of alkali and a second solvent to obtain an intermediate e, and the intermediate e and ferric chloride react in a third solvent to obtain the ferric chloride. The preparation method comprises the following steps: protecting alpha-amino and carboxyl by using L-lysine hydrochloride and hyperbranched aromatic borate, performing benzyl protection on epsilon-amino, performing boron removal protection, reacting alpha-amino with di-tert-butyl dicarbonate, and performing epsilon-aminobenzyl removal protection to obtain N-alpha-tert-butyloxycarboryl-L-lysine.

The present invention relates to a low-molecular-weight chondroitin sulfate composition, its preparation method, and application, aiming to address the problem that chondroitin sulfate products obtained by a single degradation method have limited functions and are difficult to synergistically regulate the intestinal barrier. The preparation method first prepares LMCSO by oxidative degradation; secondly, prepares LMCSH by hydrothermal degradation; and finally, prepares LMCSD by deamination degradation. Finally, the obtained LMCSO, LMCSH, and LMCSD are compounded in a weight ratio of 5:3:2 to obtain a low-molecular-weight chondroitin sulfate composition LMCSs-C. The composition LMCSs-C prepared by the present invention can synergistically improve intestinal barrier function through multiple mechanisms of action. It not only demonstrates significant intestinal barrier repair effects in vitro and in animal models, but also has good biocompatibility and safety, showing broad application prospects in maintaining intestinal health and intervening in related diseases.

This invention discloses a method for the deamination functionalization of aliphatic nitrosamines, comprising: reacting an aliphatic nitrosamine as shown in formula (II) with a nucleophile in the presence of an acid and a solvent to generate a deamination functionalized product as shown in formula (III); wherein, R 1 R 2 R 3 Each group is independently selected from hydrogen, hydroxyl, alkyl, alkoxy, alkanoyl, alkoxycarbonyl, alkylsulfinyl, alkylsulfonyl, aryl, heteroaryl, phenylalkyl, or R 1 R 2 R 3 Two or three of the functional groups form a non-aromatic ring, cage-like compound; FG is a functional group in which a nucleophile participates in the reaction. The method of this invention has the advantages of inexpensive and readily available raw materials, simple reaction conditions, and wide substrate applicability.

The invention discloses application of a methyltransferase mutant and deaminase in DNA methylation single base resolution sequencing, and relates to the technical field of gene sequencing. On the basis of a methyltransferase mutant M.MedI-N377K, cytosine at a CG site in DNA (Deoxyribonucleic Acid) can be specifically recognized, and carboxymethyl of carboxyl-S-adenosine-L-methionine (caSAM) is transferred to a C5 site of C in the CG, so that the 5-carboxymethyl cytosine is generated. 5-methylcytosine can be subjected to deamination by deaminase to form thymine, and the thymine is paired with adenine in subsequent PCR amplification; and 5cam C can resist deamination of A3A and is paired with guanine in subsequent PCR (Polymerase Chain Reaction), and 5mC is read as T and C is read as C in a subsequent Sanger sequencing result of an amplification product, so that C and 5mC in DNA (Deoxyribonucleic Acid) are distinguished. The method disclosed by the invention is high in sensitivity, good in specificity and simple to operate, does not involve hydrosulfite treatment, and can be used for carrying out positioning analysis on 5mC in a biological sample under a single-base resolution ratio.

The present invention relates to a kit for gently detecting 5hmC and a detection method thereof. The kit includes: a blocking reaction solution, an APOBEC deamination conversion solution, a pyridine borane conversion solution, a ligation reaction solution, and an amplification reaction solution; the ligation reaction solution includes probe A and probe B. First, the present invention uses glucosyltransferase to modify uridine diphosphate-glucose (UDP-Glu) on the hydroxyl group of 5hmC to form 5gmc, protecting 5hmC from being affected by subsequent reactions. Then, APOBEC is used to deaminate C and 5mC into uracil (U), and 5fC and 5caC are converted into dihydrouracil (DHU) by pyridine borane. U and DHU are complementary base-paired with A base, while 5gmc is still paired with G, so that 5hmC forms a single-base difference from other bases. The high-sensitivity detection of 5hmC is carried out by loop-mediated isothermal amplification (LAMP) based on ligation. The detection method of the present invention is gentle and efficient, can detect 5hmC as low as 2 fM, and the specificity reaches 1%.

The application discloses a method for recovering terephthalic acid from polyester-containing products, which comprises the following steps: (a) performing an enzymatic reaction by contacting the polyester-containing products with a degradation enzyme, using ammonia water / ammonia gas / liquid ammonia / ammonium hydroxide as a pH regulator in the enzymatic reaction, and forming a degradation solution containing ammonium terephthalate and a dihydric alcohol after the enzymatic reaction; (c) performing a heating treatment on the degradation solution; and (d) obtaining solid terephthalic acid through solid-liquid separation. Through the cycle mode of water dissolution-reconcentration-again deamination, the total recovery rate of PTA is significantly improved to more than 90%, efficient utilization of materials is realized, and the whole process still does not need to add acid and alkali, no waste salt is generated, and the process is green and economical.

The present invention discloses a bio-based high-strength solvent-resistant hyperbranched adhesive and a preparation method thereof, belonging to the field of bonding technology. The present invention prepares a hyperbranched polymer containing rich amino functional groups by deamination polycondensation reaction, and crosslinks it with glycerol triglycidyl ether through addition to obtain the high-strength, solvent-resistant bio-based hyperbranched adhesive MDUG adhesive of the present invention. The adhesive prepared by the present invention is widely applicable to bonding various materials, has high bonding strength and good solvent resistance, and the bonded substrate can also maintain its stability in extremely cold or high temperature environments (-196°C to 100°C), and adopts a simple solvent-free synthesis method, is easy to operate, and has low cost.

The invention relates to the technical field of microorganism culture and screening, and discloses a culture medium, a preparation method thereof and application of the culture medium in screening mineralized microorganisms, and the culture medium contains peptone, yeast extract powder, sodium chloride, magnesium chloride and calcium chloride. The culture medium takes peptone and yeast extract powder as core components, is not only suitable for screening urealysis type mineralized bacteria, but also provides nutrient substances required by growth of amino acid deamination, carbonic anhydrase catalysis or heterotrophic metabolism driven type mineralized microorganisms, comprehensively screens and prevents potential mineralized bacteria from being omitted. The culture medium can be used for accurately and efficiently screening metal surface mineralizable microorganisms. According to the culture medium, the ecological adaptability of marine strains is optimized, peptone and yeast extract powder supply nutrient substances needed by growth of marine bacteria, sodium chloride, magnesium chloride and calcium chloride are mainly used for simulating the marine salinity environment and adjusting the osmotic pressure and enzyme activity of the bacteria, the matching degree with the environment is high, and the enrichment efficiency is high.

A high pressure melamine production process wherein treating crude melamine comprises separating solid melamine from a mother liquor (1) comprising water, ammonia, carbon dioxide, residual melamine and OAT; the treatment of the mother liquor comprises deamination (100) and treatment of an ammonia depletion solution (4) in an OAT decomposition section (200); a purification treatment (300) of the OAT-depleted stream (6) produces a vapor stream (7) containing ammonia, CO2 and water and a first liquid stream (8) and a second liquid stream (9); said first liquid stream (8) comprising residual ammonia and having a CO2 concentration not greater than a target concentration; the second liquid stream (9) has an ammonia concentration not greater than a target concentration; at least part of the first liquid stream and / or at least part of the second liquid stream is recycled to the melamine production process.

The present application relates to the technical field of chemical separation, and discloses a methylamine separation and purification system and method, which can efficiently destroy hydrogen bond association system by accurately controlling flash evaporation pressure, temperature and material residence time, can recover the extraction water after removing trace organic impurities, can recover the extraction agent polarity and selectivity, can guarantee the stable separation efficiency of trimethylamine, can cut off the cross-unit pollution path from the source, can slow down the tower scaling and improve the mass transfer efficiency, can simultaneously match the whole process parameter monitoring system, can collect the operation parameters of each tower, product purity, impurity removal rate and hydrogen bond dissociation rate, can calculate the system running cycle and failure probability based on the data, and can propose the product purity stability and system energy consumption optimization strategy, so as to dynamically control the operation parameters of the whole link such as deamination, extraction, separation and recovery, and guarantee the stable output of high-purity methylamine product and the long-period continuous operation of the system.

The application discloses a system and method for extracting ammonia from solvent regenerator overhead reflux to a deamination tower, and belongs to the technical field of solvent regeneration. The system comprises a solvent regenerator, a deamination tower, a reboiler, a water cooler, a first circulating pump, a second circulating pump and a static mixer. The pipeline connecting the first circulating pump and the water cooler is connected with the pipeline connecting the second circulating pump and the static mixer through an ammonia extraction pipeline. The ammonia collected at the top of the regenerator affects the desulfurization effect of the solvent. In the application, the ammonia water collected at the top of the regenerator is sent to the deamination tower for treatment, so that the ammonia nitrogen and hydrogen sulfide contents in the amine solution after regeneration are reduced, and the amine regeneration effect is ensured. The application of the solvent regenerator overhead reflux ammonia extraction to the deamination tower to a hydrogenation device for removing hydrogen sulfide in circulating hydrogen can solve the common problem of poor desulfurization effect, and can also be applied to other naphthenic base distillate hydrogenation devices of various tonnages.

The application belongs to the technical field of organic synthesis and specifically relates to a preparation process of high-efficiency taurine. The process specifically comprises the following steps: S1, raw material solution preparation and mother liquor threshold reuse; S2, construction of an aminolysis selective chemical environment; S3, aminolysis reaction; S4, deamination and clarification filtration; S5, segmented acidification-crystallization coupling; S6, crystal throwing and controlled cooling crystallization; S7, solid-liquid separation, washing and drying; and S8, mother liquor threshold detection and closed-loop reuse. The application constructs an aminolysis selective control, acidification-crystallization purification and mother liquor threshold reuse synergistic closed-loop process, stably controls a reaction system, dynamically determines an end point, and inhibits by-product generation from the source; segmented acidification and temperature-controlled crystallization are adopted to improve the purity of crystals and the first-time pharmaceutical-grade qualified rate; and the mother liquor is recycled according to a multi-index threshold access, thereby blocking impurity accumulation.

An emission reduction device for ammonia in granulation exhaust gas from a urea production device. The emission reduction device comprises a combined tower body (1), a deamination section (2) arranged at a lower portion inside the combined tower body (1), and an ammonia recovery section (3) arranged at an upper portion inside the combined tower body; and further comprises a partition plate (7) and a gas riser (8) that are arranged between the deamination section (2) and the ammonia recovery section (3), wherein the deamination section (2) and the ammonia recovery section (3) are in gas phase communication but not in liquid phase communication. The emission reduction device can be flexibly mounted in a granulation tower or a granulation plant, has low investment costs and operation costs, and has a prolonged service life.

The invention belongs to the field of biological medicine, and particularly relates to a 12-bit deamination esterification impurity of terlipressin for injection and application. The deamination and esterification impurity is a terlipressin 12-site deamination and esterification compound generated by reaction of terlipressin 12-site amination glycine and mannitol, the molecular weight of a single isotope is 1391.5510, and the structural formula of the deamination and esterification impurity is shown as a formula I. The deamination and esterification impurity is a terlipressin 12-site deamination and esterification compound.

The invention relates to the technical field of wastewater treatment, and particularly discloses a biological deamination treatment process based on an iron-carbon coupling method. The invention discloses a biological deamination treatment process based on an iron-carbon coupling method. The biological deamination treatment process comprises the following steps: pretreatment: filling a reactor with iron-carbon composite filler with a sandwich structure; then circularly contacting the surface of the filler with an iron reducing bacteria solution and a sulfur autotrophic bacteria solution, and culturing and biofilm culturing to form a composite membrane; wherein the iron-carbon composite filler with the sandwich structure comprises two conductive net layers and an iron powder layer arranged between the two net layers; wastewater treatment: adjusting the pH and temperature of the wastewater, then introducing the wastewater into a reactor, and using hydrogen generated by iron-carbon reaction as a signal source: when the hydrogen concentration is greater than 0.5%, automatically closing aeration to enter a denitrification mode, and when the hydrogen concentration is less than 0.2%, starting aeration to convert into a nitrification mode; the composite membrane formed in the reactor continuously degrades ammonia nitrogen, and deamination treatment is completed.

This invention discloses a system and method for defluorination and ammonia removal from glass engraving wastewater. The defluorination and ammonia removal method includes the following steps: reacting glass engraving wastewater with an alkaline calcium-containing compound solution to produce a primary mixed liquid; reacting the primary mixed liquid with a fly ash suspension to obtain a secondary mixed liquid; subjecting the secondary mixed liquid to a flocculation reaction to produce a tertiary mixed liquid; filtering the tertiary mixed liquid to produce filtrate, neutralizing the filtrate with an oxalic acid solution, and then sequentially performing coagulation and flocculation reactions to produce a quaternary mixed liquid; subjecting the quaternary mixed liquid to sedimentation separation to produce a supernatant; and subjecting the supernatant to short-cut nitrification and denitrification treatment to produce a defluorinated and deammoniated supernatant. This invention uses fly ash to replace part of the slaked lime for defluorination, separates sludge and water through plate and frame filtration, adjusts the pH with oxalic acid, and adds coagulants and flocculants to achieve decalcification and hardening. The remaining oxalic acid provides a carbon source, and short-cut nitrification and denitrification are used for nitrogen removal, improving the defluorination and ammonia removal efficiency and reducing treatment costs.

The present invention relates to a method for preparing methylenequinone compounds by deamination of Mannich bases. This method involves reacting an amino acid with a Mannich base, and the organic amine on the Mannich base forms a water-soluble amide compound with the amino acid. After the reaction, it is separated from the product by washing with water. The method of the present invention avoids the problems of environmental pollution and high energy consumption caused by the traditional use of inorganic acids or acid anhydrides and distillation methods for deamination, has high reaction efficiency, is green and environmentally friendly, and is suitable for industrial production.

This invention relates to the use of a class of deaminases or transaminases and their cofactors or metabolic substrates as drugs for the treatment of polyglutamine diseases. Specifically, this invention discovers that a series of transaminases and deaminases (such as asparagine synthase ASNS) can degrade polyglutamine aggregates by deaminating polyglutamine (polyQ) proteins, thereby treating polyglutamine diseases.

The invention belongs to the field of biological medicine, and particularly relates to an impurity detection method of a terlipressin preparation for injection. The impurity is the deamination esterification impurity of terlipressin and mannitol found for the first time, the structure of the impurity is shown as a formula I and / or a formula II, and the synthesized impurity is used as a reference substance and is detected through ultra-high performance liquid chromatography.

The application relates to the field of medicine synthesis, in particular to a three-step preparation method of a ketoprofen general compound. The ketoprofen general compound is prepared through three-step reactions of deamination, deesterification and acid hydrolysis from a prepared compound of formula IV, wherein R1 is -CONR4R5, -COX1, -COOR2 or -CN at the ortho position or the para position of an amine group, R2, R3, R4 and R5 are the same or different and are H or C1-C6 alkyl, and X1 is F, Cl, Br or I. The reaction is suitable for industrial production.

The invention relates to the technical field of microorganisms and sewage treatment, in particular to a strain of European nitrosomonas and application thereof. The strain is European nitrosomonas DZ01, the strain is classified and named as Nitrosomonas europaea DZ01, and the preservation number of the strain is CCTCC (China Center for Type Culture Collection) NO: M 20241936. The European nitrosomonas DZ01 provided by the invention can tolerate a high-concentration ammonia nitrogen environment of 2000mg / L, achieves the optimal metabolic activity under the initial ammonia nitrogen concentration of 216mg / L, and realizes efficient deamination under a room temperature condition; according to the present invention, the method has characteristics of stable denitrification in the pretreated electroplating wastewater, and can maintain the deamination function in the electronic manufacturing industry wastewater containing 400 mg / L MAH, such that the stability of biological metabolism is ensured, and the ammonia nitrogen removal problem in the industrial wastewater is well solved.

The methylamine synthesis, rectification and purification system comprises a deamination unit, an extraction unit, a dehydration unit, a separation unit and an environment-friendly treatment unit, and the deamination unit comprises a deamination tower, a first tower top condenser, a first reflux tank and a first kettle liquid cooler; the extraction unit comprises an extraction tower, a second tower top condenser, a second reflux tank and a second kettle liquid cooler; the separation unit comprises a first filler rectifying tower, a third tower top condenser, a third reflux tank, a second filler rectifying tower, a fourth tower top condenser and a fourth reflux tank. According to the deamination unit disclosed by the invention, through the cooperation of the deamination tower, the first tower top condenser and other equipment, excessive liquid ammonia in a material after a synthesis reaction can be effectively removed, and the influence of ammonia on the quality of a subsequent product is reduced. Due to the two-way design of the outlet of the first reflux tank, reflux and extraction can be flexibly controlled, and the deamination efficiency and the material utilization rate are improved.

Described herein are various methods of removing uracils due to the deamination of unmethylated cytosines in an assay using engineered cytosine deaminases to deaminate methylated cytosines. The Chemoenzymatic Uracil Replacement of Nucleobases (ChURN) method includes providing a sample comprising single stranded DNA library fragments in which a cytosine deaminase has deaminated methylated cytosines; contacting the sample with an uracil DNA glycosylase (UDG) to deglycosylate uracil residues to form abasic sites having a hemiacetal formation within the single stranded DNA library fragments; contacting the sample with a reactive cytosine nucleobase analog to install a cytosine at abasic sites thru a noncanonical linkage; and subjecting the sample to polymerase chain reaction (PCR) amplification resulting in double stranded DNA corrected library fragments. The Uracil Enzymatic Removal and Substitution at Errors (U-ERASE) method includes providing a sample comprising single stranded DNA library fragments in which a cytosine deaminase has deaminated methylated cytosines, synthesizing double stranded DNA library fragments in which the second strand is tagged to facilitate its downstream degradation, treating the double stranded DNA library fragments with an uracil DNA glycosylase and an endonuclease resulting in the removal of uracil bases and single nucleotide gaps at those sites, and repairing the single nucleotide gaps through treatment with a polymerase, dCTP, and a ligase, resulting in replacement of false positive uracil bases with a mismatched base, such as cytosine. Subsequently, the second strand is selectively degraded, allowing for selective amplification of the original DNA strand via PCR.