封面
市场调查报告书
商品编码
1863974

连接酶市场按类型、形式、应用、来源、最终用户和地区划分

Ligase Enzymes Market, By Type, By Form, By Application, By Source, By End User, By Geography

出版日期: | 出版商: Coherent Market Insights | 英文 168 Pages | 商品交期: 2-3个工作天内

价格
简介目录

2025年连接酶市场规模预计为2.678亿美元,预计到2032年将达到4.385亿美元,2025年至2032年的复合年增长率为7.3%。

分析范围 分析详情
基准年 2024 市场规模(2025 年) 2.678亿美元
效能数据 2020-2024 预测期 2025-2032
预测期(2025-2032 年)复合年增长率 7.30% 预计金额(2032 年) 4.385亿美元

全球连接酶市场是生物技术和製药行业的重要组成部分,涵盖多种酶蛋白,它们透过形成共用键连接两个分子。连接酶在酵素命名系统中被归类为EC 6,在DNA复製、修復和重组等细胞过程中发挥基础性作用,使其成为分子生物学研究、诊断和治疗应用的重要工具。这些酵素利用从ATP和其他高能化合物获得的能量来催化核酸、蛋白质和其他生物分子之间形成连接键。

市场涵盖多种类型的连接酶,包括DNA连接酶、RNA连接酶和蛋白质连接酶,每种连接酶都在全球的研究机构、製药公司和生物技术公司中用于特定的应用。随着全球对精准医疗、基因治疗和个人化医疗的日益关注,对高品质连接酶的需求持续激增,推动了酵素工程和生产流程的创新。此外,连接酶在CRISPR-Cas基因编辑技术、次世代定序平台和合成生物学计划中的广泛应用也支撑着市场的成长,使其成为推动现代生物技术发展的关键组成部分。

市场动态

全球连接酶市场的主要驱动力是基因组研究的指数级增长以及基因编辑技术在製药和生物技术领域的日益普及。遗传疾病和癌症的日益普及推动了对先进诊断和治疗解决方案的需求,进而加速了分子克隆、PCR应用和DNA定序流程中对高性能连接酶的需求。此外,研发活动的大量投资,以及政府对基因组学倡议和个人化医疗计画的资助,也显着促进了市场扩张。

连接酶在合成生物学、疫苗研发和生物製药生产中的应用日益广泛,也推动了市场成长,因为这些酵素对于建构重组DNA分子和开发新型治疗性蛋白质至关重要。然而,连接酶的应用也存在诸多局限性,包括酵素生产和纯化成本高成本、酵素製剂产品监管要求严格,以及酵素稳定性及储存条件的技术挑战。

酵素生产的复杂性以及操作这些生物催化剂所需的专业知识,也对小型企业构成了市场进入障碍。儘管存在这些挑战,但连接酶在液态生物检体诊断、就地检验设备以及包括mRNA疫苗和基因治疗载体在内的新一代治疗方法等新兴领域的应用不断扩展,带来了巨大的机会,为市场参与企业提供了利用不断发展的生物技术趋势获利的良机。

本报告的主要特点

  • 本报告对全球连接酶市场进行了详细分析,并以 2024 年为基准年,给出了预测期(2025-2032 年)的市场规模和復合年增长率。
  • 它还重点介绍了各个细分市场的潜在商机,并描述了该市场中一系列有吸引力的投资提案。
  • 它还提供了有关市场驱动因素、限制因素和机会、新产品发布和核准、市场趋势、区域展望以及主要企业采取的竞争策略的关键见解。
  • 全球连接酶市场的主要企业概况、产品系列、主要亮点、财务表现和策略等参数均已列出。
  • 本报告提供的见解将使负责人和企业经营团队能够就未来的产品发布、合作关係、市场扩张和行销策略做出明智的决策。
  • 《全球连接酶市场》报告涵盖了该行业的各个相关人员,包括投资者、供应商、产品製造商、经销商、新进入者和金融分析师。
  • 相关人员可以透过用于分析全球连接酶市场的各种策略矩阵更轻鬆地做出决策。

目录

第一章 分析目标和先决条件

  • 分析目的
  • 先决条件
  • 简称

第二章 市场展望

  • 报告说明
    • 市场定义和范围
  • 执行摘要

第三章:市场动态、监管与趋势分析

  • 市场动态
  • 司机
  • 抑制因素
  • 机会
  • 影响分析
  • 重大进展
  • 监管情景
  • 产品发布/核准
  • PEST分析
  • 波特五力分析
  • 企业合併情景
  • 产业趋势

第四章 全球连结酶市场(按类型划分)(2020-2032 年)

  • 介绍
  • DNA连接酶
  • RNA连接酶
  • 其他连接酶(例如,胜肽连接酶、蛋白质连接酶)

5. 全球连结酶市场(按形式划分)(2020-2032 年)

  • 介绍
  • 液体配方
  • 冻干粉

6. 全球连结酶市场按应用领域划分(2020-2032 年)

  • 介绍
  • 研究与开发
  • 克隆和诱变
  • 次世代定序(NGS)文库製备
  • DNA合成与组装(例如,吉布森组装)
  • SNP检测和基因分型
  • 其他研究
  • 诊断
  • 分子诊断检测(例如,LAMP、PCR)
  • 感染疾病检测
  • 识别其他遗传疾病
  • 治疗药物
  • 药物发现与开发
  • 基因治疗载体构建
  • 其他(例如,质体构建)

7. 全球连结酶市场(依来源划分)(2020-2032 年)

  • 介绍
  • 微生物(细菌、病毒等)
  • 动物
  • 植物

8. 全球连结酶市场(按最终用户划分)(2020-2032 年)

  • 介绍
  • 製药和生物技术公司
  • 医院和诊断实验室
  • 合约研发生产组织(CRO/CMO)
  • 学术研究机构

9. 全球连结酶市场(按地区划分)(2020-2032 年)

  • 介绍
  • 北美洲
      • 美国
      • 加拿大
  • 拉丁美洲
      • 巴西
      • 阿根廷
      • 墨西哥
      • 其他拉丁美洲
  • 欧洲
      • 德国
      • 英国
      • 西班牙
      • 法国
      • 义大利
      • 俄罗斯
      • 其他欧洲
  • 亚太地区
      • 中国
      • 印度
      • 日本
      • 澳洲
      • 韩国
      • ASEAN
      • 亚太其他地区
  • 中东
      • 海湾合作委员会国家
      • 以色列
      • 其他中东地区
  • 非洲
      • 南非
      • 北非
      • 中非

第十章 竞争格局

  • New England Biolabs
  • Creative Enzymes.
  • Thermo Fisher Scientific
  • QIAGEN NV
  • Promega Corporation
  • Merck KGaA
  • Takara Bio Inc.
  • Agilent Technologies
  • Bio-Rad Laboratories
  • ArcticZymes Technologies
  • Codexis, Inc.
  • Lonza Group
  • BioCat GmbH
  • Lucigen Corporation
  • Enzo Life Sciences

第十一章 分析师建议

  • 机会
  • 分析师观点
  • Coherent Opportunity Map (COM)

第十二章 参考文献与分析方法

  • 参考
  • 分析方法
  • 关于 Coherent Market Insights
简介目录
Product Code: CMI8760

Ligase Enzymes Market is estimated to be valued at USD 267.8 Mn in 2025 and is expected to reach USD 438.5 Mn by 2032, growing at a compound annual growth rate (CAGR) of 7.3% from 2025 to 2032.

Report Coverage Report Details
Base Year: 2024 Market Size in 2025: USD 267.8 Mn
Historical Data for: 2020 To 2024 Forecast Period: 2025 To 2032
Forecast Period 2025 to 2032 CAGR: 7.30% 2032 Value Projection: USD 438.5 Mn

The global ligase enzymes market represents a critical segment within the biotechnology and pharmaceutical industries, encompassing a diverse array of enzymatic proteins that facilitate the joining of two molecules through the formation of covalent bonds. Ligase enzymes, classified as EC 6 in the enzyme nomenclature system, play fundamental roles in cellular processes including DNA replication, repair, and recombination, making them indispensable tools in molecular biology research, diagnostics, and therapeutic applications. These enzymes catalyze the formation of bonds between nucleic acids, proteins, and other biomolecules by utilizing energy from ATP or other high-energy compounds.

The market encompasses various types of ligases, including DNA ligases, RNA ligases, and protein ligases, each serving specific applications in research laboratories, pharmaceutical companies, and biotechnology firms worldwide. As the global focus on precision medicine, gene therapy, and personalized healthcare intensifies, the demand for high-quality ligase enzymes continues to surge, driving innovation in enzyme engineering and manufacturing processes. The market's growth trajectory is further supported by expanding applications in CRISPR-Cas gene editing technologies, next-generation sequencing platforms, and synthetic biology initiatives, positioning ligase enzymes as essential components in advancing modern biotechnological capabilities.

Market Dynamics

The global ligase enzymes market is primarily driven by the exponential growth in genomics research and the increasing adoption of gene editing technologies across pharmaceutical and biotechnology sectors. The rising prevalence of genetic disorders and cancer has intensified the demand for advanced diagnostic and therapeutic solutions, propelling the need for high-performance ligase enzymes in molecular cloning, PCR applications, and DNA sequencing procedures. Additionally, substantial investments in research and development activities, coupled with government funding for genomics initiatives and personalized medicine programs, are significantly boosting market expansion.

The growing applications of ligase enzymes in synthetic biology, vaccine development, and biopharmaceutical manufacturing further contribute to market growth, as these enzymes are essential for constructing recombinant DNA molecules and developing novel therapeutic proteins. However, the market faces notable restraints including the high cost of enzyme production and purification processes, stringent regulatory requirements for enzyme-based products, and technical challenges associated with enzyme stability and storage conditions.

The complexity of enzyme manufacturing and the need for specialized expertise in handling these biological catalysts also pose barriers to market entry for smaller players. Despite these challenges, significant opportunities emerge from the expanding applications of ligase enzymes in emerging fields such as liquid biopsy diagnostics, point-of-care testing devices, and next-generation therapeutic modalities including mRNA vaccines and gene therapy vectors, creating lucrative prospects for market participants to capitalize on evolving biotechnological trends.

Key Features of the Study

  • This report provides in-depth analysis of the global ligase enzymes market, and provides market size (USD Million) and compound annual growth rate (CAGR%) for the forecast period (2025-2032), considering 2024 as the base year
  • It elucidates potential revenue opportunities across different segments and explains attractive investment proposition matrices for this market
  • This study also provides key insights about market drivers, restraints, opportunities, new product launches or approvals, market trends, regional outlook, and competitive strategies adopted by key players
  • It profiles key players in the global ligase enzymes market based on the following parameters - company highlights, products portfolio, key highlights, financial performance, and strategies
  • Key companies covered as a part of this study include New England Biolabs, Creative Enzymes., Thermo Fisher Scientific, QIAGEN N.V., Promega Corporation, Merck KGaA, Takara Bio Inc., Agilent Technologies, Bio-Rad Laboratories, ArcticZymes Technologies, Codexis, Inc., Lonza Group, BioCat GmbH, Lucigen Corporation, and Enzo Life Sciences
  • Insights from this report would allow marketers and the management authorities of the companies to make informed decisions regarding their future product launches, type up-gradation, market expansion, and marketing tactics
  • The global ligase enzymes market report caters to various stakeholders in this industry including investors, suppliers, product manufacturers, distributors, new entrants, and financial analysts
  • Stakeholders would have ease in decision-making through various strategy matrices used in analyzing the global ligase enzymes market

Market Segmentation

  • Type Insights (Revenue, USD Mn, 2020 - 2032)
    • DNA Ligases
    • RNA Ligases
    • Other Ligases (e.g., Peptide Ligases, Protein Ligases)
  • Form Insights (Revenue, USD Mn, 2020 - 2032)
    • Liquid Formulations
    • Lyophilized Powders
  • Application Insights (Revenue, USD Mn, 2020 - 2032)
    • Research and Development
    • Cloning and Mutagenesis
    • Next-Generation Sequencing (NGS) Library Preparation
    • DNA Synthesis and Assembly (e.g., Gibson Assembly)
    • SNP Detection and Genotyping
    • Other Research
    • Diagnostics
    • Molecular Diagnostic Assays (e.g., LAMP, PCR-based tests)
    • Infectious Disease Detection
    • Other Genetic Disorder Identification
    • Therapeutics
    • Drug Discovery and Development
    • Gene Therapy Vector Construction
    • Others (e.g., Plasmid Construction)
  • Source Insights (Revenue, USD Mn, 2020 - 2032)
    • Microorganisms (Bacteria, Virus, Others)
    • Animal
    • Plant
  • End User Insights (Revenue, USD Mn, 2020 - 2032)
    • Pharmaceutical and Biotechnology Companies
    • Hospitals and Diagnostic Laboratories
    • Contract Research and Manufacturing Organizations (CROs/CMOs)
    • Academic and Research Institutes
  • Regional Insights (Revenue, USD Mn, 2020 - 2032)
    • North America
    • U.S.
    • Canada
    • Latin America
    • Brazil
    • Argentina
    • Mexico
    • Rest of Latin America
    • Europe
    • Germany
    • U.K.
    • Spain
    • France
    • Italy
    • Russia
    • Rest of Europe
    • Asia Pacific
    • China
    • India
    • Japan
    • Australia
    • South Korea
    • ASEAN
    • Rest of Asia Pacific
    • Middle East
    • GCC Countries
    • Israel
    • Rest of Middle East
    • Africa
    • South Africa
    • North Africa
    • Central Africa
  • Key Players Insights
    • New England Biolabs
    • Creative Enzymes.
    • Thermo Fisher Scientific
    • QIAGEN N.V.
    • Promega Corporation
    • Merck KGaA
    • Takara Bio Inc.
    • Agilent Technologies
    • Bio-Rad Laboratories
    • ArcticZymes Technologies
    • Codexis, Inc.
    • Lonza Group
    • BioCat GmbH
    • Lucigen Corporation
    • Enzo Life Sciences

Table of Contents

1. Research Objectives and Assumptions

  • Research Objectives
  • Assumptions
  • Abbreviations

2. Market Purview

  • Report Description
    • Market Definition and Scope
  • Executive Summary
    • Global Ligase Enzymes Market, By Type
    • Global Ligase Enzymes Market, By Form
    • Global Ligase Enzymes Market, By Application
    • Global Ligase Enzymes Market, By Source
    • Global Ligase Enzymes Market, By End User
    • Global Ligase Enzymes Market, By Region

3. Market Dynamics, Regulations, and Trends Analysis

  • Market Dynamics
  • Driver
  • Restraint
  • Opportunity
  • Impact Analysis
  • Key Developments
  • Regulatory Scenario
  • Product Launches/Approvals
  • PEST Analysis
  • PORTER's Analysis
  • Merger and Acquisition Scenario
  • Industry Trends

4. Global Ligase Enzymes Market, By Type, 2020-2032, (USD Mn)

  • Introduction
    • Market Share Analysis, 2025 and 2032 (%)
    • Y-o-Y Growth Analysis, 2021 - 2032
    • Segment Trends
  • DNA Ligases
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • RNA Ligases
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Other Ligases (e.g., Peptide Ligases, Protein Ligases)
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)

5. Global Ligase Enzymes Market, By Form, 2020-2032, (USD Mn)

  • Introduction
    • Market Share Analysis, 2025 and 2032 (%)
    • Y-o-Y Growth Analysis, 2021 - 2032
    • Segment Trends
  • Liquid Formulations
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Lyophilized Powders
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)

6. Global Ligase Enzymes Market, By Application, 2020-2032, (USD Mn)

  • Introduction
    • Market Share Analysis, 2025 and 2032 (%)
    • Y-o-Y Growth Analysis, 2021 - 2032
    • Segment Trends
  • Research and Development
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Cloning and Mutagenesis
  • Next-Generation Sequencing (NGS) Library Preparation
  • DNA Synthesis and Assembly (e.g., Gibson Assembly)
  • SNP Detection and Genotyping
  • Other Research
  • Diagnostics
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Molecular Diagnostic Assays (e.g., LAMP, PCR-based tests)
  • Infectious Disease Detection
  • Other Genetic Disorder Identification
  • Therapeutics
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Drug Discovery and Development
  • Gene Therapy Vector Construction
  • Others (e.g., Plasmid Construction)

7. Global Ligase Enzymes Market, By Source, 2020-2032, (USD Mn)

  • Introduction
    • Market Share Analysis, 2025 and 2032 (%)
    • Y-o-Y Growth Analysis, 2021 - 2032
    • Segment Trends
  • Microorganisms (Bacteria, Virus, Others)
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Animal
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Plant
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)

8. Global Ligase Enzymes Market, By End User, 2020-2032, (USD Mn)

  • Introduction
    • Market Share Analysis, 2025 and 2032 (%)
    • Y-o-Y Growth Analysis, 2021 - 2032
    • Segment Trends
  • Pharmaceutical and Biotechnology Companies
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Hospitals and Diagnostic Laboratories
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Contract Research and Manufacturing Organizations (CROs/CMOs)
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)
  • Academic and Research Institutes
    • Introduction
    • Market Size and Forecast, and Y-o-Y Growth, 2020-2032, (USD Mn)

9. Global Ligase Enzymes Market, By Region, 2020 - 2032, Value (USD Mn)

  • Introduction
    • Market Share (%) Analysis, 2025, 2028 & 2032, Value (USD Mn)
    • Market Y-o-Y Growth Analysis (%), 2021 - 2032, Value (USD Mn)
    • Regional Trends
  • North America
    • Introduction
    • Market Size and Forecast, By Type, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Form, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Application, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Source, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By End User, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Country, 2020 - 2032, Value (USD Mn)
      • U.S.
      • Canada
  • Latin America
    • Introduction
    • Market Size and Forecast, By Type, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Form, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Application, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Source, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By End User, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Country, 2020 - 2032, Value (USD Mn)
      • Brazil
      • Argentina
      • Mexico
      • Rest of Latin America
  • Europe
    • Introduction
    • Market Size and Forecast, By Type, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Form, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Application, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Source, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By End User, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Country, 2020 - 2032, Value (USD Mn)
      • Germany
      • U.K.
      • Spain
      • France
      • Italy
      • Russia
      • Rest of Europe
  • Asia Pacific
    • Introduction
    • Market Size and Forecast, By Type, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Form, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Application, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Source, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By End User, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Country, 2020 - 2032, Value (USD Mn)
      • China
      • India
      • Japan
      • Australia
      • South Korea
      • ASEAN
      • Rest of Asia Pacific
  • Middle East
    • Introduction
    • Market Size and Forecast, By Type, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Form, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Application, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Source, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By End User, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Country, 2020 - 2032, Value (USD Mn)
      • GCC Countries
      • Israel
      • Rest of Middle East
  • Africa
    • Introduction
    • Market Size and Forecast, By Type, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Form, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Application, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Source, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By End User, 2020 - 2032, Value (USD Mn)
    • Market Size and Forecast, By Country/Region, 2020 - 2032, Value (USD Mn)
      • South Africa
      • North Africa
      • Central Africa

10. Competitive Landscape

  • New England Biolabs
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Creative Enzymes.
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Thermo Fisher Scientific
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • QIAGEN N.V.
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Promega Corporation
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Merck KGaA
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Takara Bio Inc.
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Agilent Technologies
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Bio-Rad Laboratories
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • ArcticZymes Technologies
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Codexis, Inc.
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Lonza Group
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • BioCat GmbH
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Lucigen Corporation
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies
  • Enzo Life Sciences
    • Company Highlights
    • Product Portfolio
    • Key Developments
    • Financial Performance
    • Strategies

11. Analyst Recommendations

  • Wheel of Fortune
  • Analyst View
  • Coherent Opportunity Map

12. References and Research Methodology

  • References
  • Research Methodology
  • About Us