Name: caring for research mice and rats
Uploaded: 2016-09-14T17:37:02.000Z
Duration: 13 min 24 s
Channel: JoVE

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Life Science

Structure and Function

HS-LS1-2.

Basic Care Procedures

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作必须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。
1. 免疫功能健全（常规）小鼠的处理
研究表明，小鼠的免疫系统疾病与人类非常相似。由于这些动物的免疫能力有限，因此在饲养和护理过程中已设计出相应的操作规程，通过使用工程控制措施、动物护理人员的个人防护装备以及标准操作程序，以最大限度地降低感染性疾病的风险；这些措施可有效减少动物接触的笼具及其他设备受到污染的可能性。
<ol>
	<li>从运输容器中拆包：接收来自其他机构或动物供应商的动物会对动物设施内已饲养的动物带来风险。在运输过程中，动物运输箱可能接触到病原体。因此，在拆开运输容器时应遵循正确的操作程序。
	<ol>
		<li>处理动物时，最低限度的个人防护装备（PPE）要求包括手套、洁净的实验服或刷手服、颗粒物防护口罩和护目镜。</li>
		<li>选择合适的笼具，包括带金属网盖的笼盖和屏障顶盖。笼具内应配备适当的垫料和筑巢材料。所有笼具应在动物到达前准备妥当并放置于接收区域。</li>
		<li>动物到达后，将运输箱置于安全且温控的房间内，然后检查容器是否有损坏。</li>
		<li>使用适当的消毒剂对运输容器的外表面进行消毒，以杀灭任何有害病原体。确保消毒剂与箱体接触时间符合制造商的建议，通常为15–30分钟。</li>
		<li>将容器放入动物转移站（ATS）中。ATS在罩内提供经HEPA过滤的气流，通过在操作者与工作区之间形成负压空气屏障，提供过敏原防护。这可最大程度减少动物毛发/皮屑和笼具垫料材料的暴露。单向气流还可保护动物免受周围房间空气的影响，降低污染风险。</li>
		<li>打开运输容器后，评估动物的整体健康状况，并记录任何受伤或生病的动物。</li>
		<li>将动物按适当群体大小放入组装好的笼具中。分组应符合空间管理规定以及其将要参与的实验方案要求。</li>
		<li>用金属网盖盖住笼具，并固定网盖上的隔板，将网盖分为两个区域。</li>
		<li>选择合适的食物，并将其放置在金属网盖的一侧，另一侧保持开放，以利于空气流通。</li>
		<li>通过饮水瓶或自动供水系统提供饮水。新生断奶小鼠使用饮水瓶，以确保其能够维持足够的水合水平。对于配备自动供水系统的IVC笼具，在将笼具放上架子前需对供水管进行充水。</li>
		<li>将笼具放置在架子上。若使用IVC笼具，需检查笼具是否完全卡入架子，并确认吸水管已牢固连接至供水系统。</li>
	</ol>
	</li>
	<li>常规小鼠笼具更换
	<ol>
		<li>动物笼具在动物转移站（ATS）内进行更换。每次操作结束后应对ATS进行消毒。</li>
		<li>每次只能打开一个笼具。</li>
		<li>将已准备好适当垫料和筑巢材料的笼具带入动物房，并将少量笼具放入ATS中。</li>
		<li>配备内置吸水管的IVC笼具必须预先充水，以迫使水进入吸水管，排出吸水管内的空气死腔。若未正确充水，小鼠可能无法对吸水管施加足够压力以排出其中的空气。</li>
		<li>处理动物时，最低限度的个人防护装备（PPE）要求包括手套、洁净的实验服或刷手服、颗粒物防护口罩和护目镜。</li>
		<li>待更换的动物笼具被移入新笼具后，再放入ATS中。</li>
		<li>使用适当的抓取技术（如手捧法或隧道法）转移动物，以尽量减少应激。在不同笼具之间或不同小鼠组之间应更换手套，或使用无毒化学消毒剂对手套进行消毒。</li>
		<li>研究表明，将小鼠的筑巢区域一并转移至清洁笼具中，有助于其适应新环境，尤其是群养雄性小鼠。其他环境丰富化物品也应一同转移至新笼具。</li>
		<li>当笼盖或饲料器放置到新笼具后，添加饲料。</li>
		<li>将屏障顶盖盖在新笼具上，然后将笼具放回架子。</li>
		<li>IVC笼具必须正确对接至架子，以确保通风和供水阀门正常启动。</li>
	</ol>
	</li>
</ol>
2. 免疫缺陷小鼠的处理
<ol>
	<li>从运输集装箱中拆箱
	<ol>
		<li>免疫缺陷动物必须在无菌条件下拆包。所有操作免疫缺陷小鼠的人员必须穿戴经蒸汽灭菌的实验服、口罩、头帽和无菌手套。在处理这些动物时，应始终采用无菌技术。</li>
		<li>所有设备和笼具应通过蒸汽、紫外线辐射灭菌，或使用消毒剂浸泡进行化学灭菌&#160; 至少30分钟。无菌笼具的处理有两种选择：一种是经过包裹并采用蒸汽灭菌的标准笼具，另一种是由供应商通过辐照等方式灭菌的笼具。这些笼具均为一次性使用单元。</li>
		<li>在超净工作台内操作小鼠前，需在开启风机的情况下，用适当的消毒剂喷洒工作台内部。风机应始终保持开启状态，以维持无菌环境。每次使用后，需用消毒剂喷洒工作台，清除所有残留物，再用70%乙醇喷洒一遍。</li>
		<li>理想情况下，接收免疫缺陷小鼠需要两人配合：一人使用无菌技术操作动物（无菌操作员），另一人处理污染物品（非无菌操作员）。非无菌操作员仍应穿戴洁净的长袖防护服、实验服或罩衫、口罩、头罩及无菌手套，以防在需要伸入生物安全柜时污染无菌内部环境。</li>
		<li>准备层流罩，方法如前所述。建议使用专用于免疫缺陷动物的层流罩。层流罩应配备紫外线（UV）杀菌灯，用于在使用间隔对罩内进行消毒。需使用定时器，以确保层流罩表面得到充分的紫外线照射。</li>
		<li>将所有放入生物安全柜的物品外部喷洒适当的消毒剂，包括食物、水和笼具的外包装。</li>
		<li>在将运输箱放入生物安全柜之前，需喷洒适当的消毒剂。放入生物安全柜后，运输箱须保持封闭状态15-30分钟。</li>
		<li>指定的动物操作人员在超净台内打开无菌饲料和水。</li>
		<li>非无菌操作人员在超净工作台内打开运输箱。非无菌操作人员须注意避免接触超净台内表面及运输箱内部。</li>
		<li>实验操作人员打开无菌笼盒，在笼盖上放置食物和水，完成笼盒的准备工作。随后将小鼠从运输箱中取出，放入无菌笼盒中。</li>
		<li>由无菌动物操作人员记录动物状况。任何表现异常或有明显损伤的动物将被隔离。所有标记为需要兽医关注的动物笼具，将最后进行处理、换笼或实验操作，以减少对其他动物的潜在污染。</li>
		<li>非无菌操作人员将把装有动物的笼盒从罩内移出。笼盒可作为静态笼盒放置在标准笼架上，或作为独立通气笼盒（IVCs）放置在通风笼架上。对于独立通气笼盒（IVCs）中的小鼠，应提供额外的筑巢材料以帮助其体温调节。</li>
		<li>动物饲养员应在处理每个运输容器后更换手套，以避免不同动物群体之间可能的交叉污染。运输容器编号应记录在笼具卡片上，以便在动物出现疾病时追踪其来源。</li>
		<li>未使用的物品只要原容器能够重新密封，即可保存以供将来使用。未食用的食物需从房间内移除。</li>
		<li>小鼠在用于实验前应至少经过一周的适应期。</li>
	</ol>
	</li>
	<li>免疫缺陷小鼠的换笼操作
	<ol>
		<li>小鼠笼具每周至少更换一次，必要时可增加更换频率。</li>
		<li>准备生物安全柜、准备笼具以及人员个人防护装备的步骤与动物拆包时相同。</li>
		<li>动物应通过杯式抓取法或隧道式抓取法进行转移，以尽量减少应激。指定的动物操作人员应在每处理5–10个笼盒后、手套破损或受到污染时，或发现动物出现疾病症状时，更换手套。</li>
		<li>任何出现动物生病迹象的笼具将被安排在换笼顺序的最后，以避免健康动物可能暴露于病原体或污染物。</li>
		<li>如果在下次计划更换笼具之前需要向笼内添加食物和/或水，则必须在准备好的生物安全柜中以无菌操作方式进行。</li>
	</ol>
	</li>
</ol>
关键术语与定义 
饲养/笼具 
小鼠和大鼠主要饲养在底部为实心、内含垫料的鞋盒式笼具中。标准的小鼠鞋盒笼提供75平方英寸的底面积，足以容纳最多五只成年小鼠。然而，实验设计可能要求每组四只小鼠。在此情况下，应在接收动物时即按四只一组进行分组饲养，以避免实验开始时对社会群体造成干扰。通常，大鼠笼具最多可容纳两只完全成年的动物。若大鼠需长期饲养，应采用成对饲养方式。笼具可以是静态的，也可以是独立通风笼具（IVC）。静态笼具上方覆盖金属网盖，或放置在架子上，由上方的隔板作为笼顶。过滤材料可作为罩帽覆盖在金属网盖上，或作为滤纸片覆盖在架子隔板上。IVC由笼体、金属网盖和罩帽组成，放置在提供气流进入笼内的架子上。使用IVC可减少更换笼具的频率，相较于静态笼具更少更换。标准笼具系统提供水源和饲料分配区域。&#160; 
水源可通过置于笼顶的水瓶提供，也可通过饮水管供给，饮水管是动物笼具的内置组件。当笼具安装到架子上时，水被输送到饮水管中，构成自动供水系统，旨在满足整个动物设施内动物的饮水需求。笼具必须正确准备，以确保动物得到适当护理。饲料可通过置于笼内的饲喂器提供，或利用金属网盖的一部分区域储存饲料。饲料放置位置应避免被动物污染。《实验动物护理与使用指南》（&#34;指南&#34;）规定，所有笼具设备必须至少每两周消毒一次。某些笼具及配件可能需要更频繁更换，具体取决于 enclosure 内的气味和氨气水平。通常，IVC 每两周更换一次，除非笼内饲养四只或以上雄性小鼠，或一只带仔雌鼠；此类 enclosure 可能需要每周更换。由于换笼过程可能使免疫缺陷小鼠暴露于病原体，因此对免疫缺陷小鼠的笼具更换应尽可能减少频率。 
饮食 
现有多种饲料配方，其蛋白质、碳水化合物和脂肪含量各不相同。通常，饲料应包含15–19%的蛋白质、44%的碳水化合物以及4–9%的脂肪。高脂肪饲料常用于繁殖种群，以促进生殖能力。由于饲料可能成为免疫缺陷小鼠的污染源，必须经过蒸汽灭菌或辐照处理。经高压灭菌处理的饲料需特别配制以耐受该过程。然而，辐照处理不会改变饲料成分。水是免疫缺陷动物另一潜在污染源。水应通过高压灭菌或过滤处理，后者包括使水通过紫外线滤器。在高压灭菌器中对水进行蒸汽灭菌时，需用铝箔覆盖单个水瓶。带饮水管的瓶盖则需单独装入高压灭菌袋中灭菌。自动供水系统可配合一系列过滤装置使用，包括颗粒过滤器和紫外线灯过滤器。 
环境 
动物饲养设施内的环境条件必须严格控制。联邦法规和指南已为常用实验动物的护理与操作制定了标准。光照、环境温度、湿度和气流均需满足动物的生理需求。除免疫缺陷动物需要略高的室温外，其余参数与常规动物相同。无胸腺裸鼠还需在笼内额外提供垫料和纸条类筑巢材料，以辅助体温调节。 
动物房应维持在68–72°F的温度范围内，相对湿度为40–60%。湿度低于40%可能导致小鼠和大鼠出现环尾症，即尾部皮肤干燥并紧缩缠绕尾部，严重时可导致尾部组织脱落。光照周期应设置合理，避免因光周期或光照强度不当而对动物造成应激。通常采用12小时光照、12小时黑暗的光周期。光照强度应根据房间内的活动情况调整。技术人员在动物房工作时可使用较高光照强度，但在所有操作结束后应将光照降低至约325勒克斯（lux）。灯光应由定时器控制，并通过监测系统验证光周期的准确性。根据《指南》要求，动物房每小时必须至少进行10–15次完全新鲜空气的换气。换气有助于减少动物房内的微生物和异味。在动物密度较高的房间，每小时换气次数可能需要增加。 
笼具层面的环境因素包括笼具类型、笼内使用的基质、供水系统和饮食。除科学理由充分或动物与其他个体完全不相容外，社会性群养为强制要求。提供环境丰富化措施，如纸质小屋和筑巢材料，可使动物表现出物种特异性行为，从而降低应激水平，提升整体福利。筑巢材料还能形成富含镇静信息素的睡眠区域，有助于在同一笼内饲养多只雄性小鼠。在更换笼具时，应将原有的筑巢材料转移至清洁笼中，以帮助减少雄性小鼠进入新环境时可能发生的攻击行为。 
本视频将帮助您解答的问题 
在生物医学研究中，实验动物的正确护理与操作对实验结果至关重要。相关法规和既定指南规定了许多操作规范。然而，对于具有免疫缺陷的小鼠和大鼠，还需采取额外措施，以防止其意外暴露于机会性病原体。当操作严格遵循既定程序时，实验动物的健康与福利得以提升，从而获得更可靠的实验结果。

基础护理操作程序

来源： Kay Stewart, RVT, RLATG, CMAR；Valerie A. Schroeder, RVT, RLATG。印第安纳州，圣母大学
小鼠和大鼠在生物医学研究中所使用的动物中占很大比例。保障其福利既是伦理责任，也是确保科学有效性的关键。大多数小鼠和大鼠适用一些通用操作规程，但某些动物（如免疫缺陷个体）则需要采取额外措施以维持其存活并用于实验。
常用的免疫缺陷小鼠包括在近交系小鼠中自然发生的突变品系，以及通过基因工程技术构建的品系。最早用于科研的免疫缺陷小鼠是&#34;裸鼠&#34;。BALB/c 裸鼠（nu）于1966年在一个BALB/c小鼠群体中被发现，该群体中部分小鼠表现为无毛且缺乏胸腺。这些无胸腺小鼠的免疫系统受到抑制，体内缺乏T细胞。人们很快发现这种动物在微生物感染、免疫缺陷和自身免疫疾病研究中具有重要价值。尽管使用频率不及裸鼠，也存在裸鼠大鼠品系。裸鼠大鼠同样缺乏T细胞，并在外周淋巴器官的胸腺依赖区表现出细胞群体减少。另一种自然发生的免疫缺陷小鼠是重度联合免疫缺陷小鼠（SCID）。这类小鼠存在基因缺陷，导致无法正常产生功能性B细胞和T细胞。由于不能启动有效的免疫应答，这些小鼠可作为人类细胞移植的宿主。目前已有多种携带免疫缺陷的基因修饰小鼠品系实现商业化供应。其免疫缺陷程度因具体的基因修饰而异；然而，所有免疫缺陷小鼠和大鼠在饲养与操作过程中均需采取相似的管理措施。

本文将介绍免疫功能正常和免疫功能低下动物的护理。将针对这两类动物的饲养、饮食、环境需求以及操作处理进行讨论

来源：Kay Stewart，RVT，RLATG，CMAR；Valerie A. Schroeder，RVT，RLATG。美国印第安纳州圣母大学  
小鼠和大鼠占实验动物的很大比例……

由于小鼠和大鼠在生物医学研究中所使用的动物中占很大比例，确保其福利既是伦理责任，也是保证科学研究有效性的关键。&#160; 
动物护理程序从接收运输容器中的动物开始，持续进行笼具更换、适当饲养、提供合理营养以及环境管理。&#160; 
这些操作应遵循机构指南以及“3R原则”（尤其是优化原则），以尽量减少动物应激并促进其健康福祉。&#160; 
本视频介绍了实验动物护理的标准和基本操作流程。&#160; 
从其他机构接收动物存在引入病原体的风险；因此，在拆开运输箱时应遵循正确的操作程序。 
在接触任何动物之前，必须穿戴适当的个人防护装备（PPE）。&#160; 
最低限度的PPE包括实验服、手套、护目镜和外科口罩，这些装备有助于减少粉尘和过敏原的暴露，并降低对动物造成污染的风险。&#160; 
下一步是为 incoming 动物选择合适的笼具，然后在笼内放置适当的垫料和筑巢材料，并在动物到达前将准备好的笼具放入温控接收室。 
运输箱到达后，将其放置在接收室内的安全区域。检查容器是否有损坏，并对表面进行消毒，以减少潜在污染。&#160; 
确保消毒剂与箱体接触时间符合制造商建议。然后将容器放入动物转移站（ATS）中。 
该工作站提供经HEPA过滤的单向气流，可减少空气中的污染物，保护工作人员和动物。 
接下来，打开运输箱并评估啮齿类动物的整体健康状况。任何出现受伤或疾病迹象的动物都应按照机构兽医指南上报并进行处理。 
随后，根据物种、性别和相容性，将动物以适当的群体大小放入已准备好的笼具中，&#160;盖上金属丝网盖，并在需要时固定分隔板。&#160; 
选择合适的食物并将其放置在笼具指定区域。最后，添加饮水瓶以确保充足的供水。请注意，每次操作结束后必须对ATS进行消毒，且消毒过程中风机必须保持开启。 
进行笼具更换时，将两个笼具——一个装有适当垫料的新笼和一个装有动物的旧笼——放入ATS中。应采用适当的抓取技术（如手捧法或隧道法）转移动物，以尽量减少应激。&#160; 
每次只能打开一个笼具。对于雄性小鼠或带有幼崽的雌性小鼠，研究表明，将原笼中的筑巢区域转移到清洁笼具中，有助于动物适应新环境。&#160; 
当新笼盖放置到位后，将旧笼盖上的清洁饲料转移到新笼盖上，并在必要时补充更多饲料。&#160; 
接下来安装屏障盖，并将笼具放回笼架。建议在不同笼具或群体之间更换手套。 
对于免疫缺陷动物的拆包操作，必须维持无菌条件。建议在使用前开启罩内风机，以建立适当的气流。 
与免疫功能正常动物类似，运输箱到达后应使用适当的消毒剂喷洒容器，并按制造商建议保持封闭状态。 
在专用于免疫缺陷小鼠的ATS中，操作动物前应使用适当的消毒剂对层流罩进行消毒。&#160; 
理想情况下，此拆包过程可由两名人员协作完成：一名无菌技术人员以无菌方式处理动物，另一名非无菌技术人员处理受污染物品。两者均需穿戴适当的PPE。 
在罩内打开运输箱之前，应将所有用品和笼具放入罩内，并使用适当的消毒剂对其外表面进行消毒。&#160; 
灭菌笼具可以是可重复使用的高压灭菌笼具，也可以是一次性使用的无菌即用型笼具。 
非无菌人员拆开无菌笼具包装，并以无菌方式传递给动物操作员，后者取下罩帽和金属丝网盖，并将其放入罩内而不污染内表面。&#160; 
动物操作员应根据需要更换外层手套，以维持无菌操作。 
随后，在罩内工作站处为笼具的饮水管注水。最后，动物操作员将动物放入笼具，用金属丝网盖固定，添加饲料并安装罩帽。请注意，罩内风机应始终保持开启，以维持&#160;无菌条件。 
操作结束时，非无菌人员将已装入动物的笼具从罩内取出，并放置在合适的笼架上。&#160; 
现在我们来讨论动物的适当饲养条件，这是提供基本护理的另一个重要方面。&#160; 
小鼠和大鼠通常饲养在底部实心、内含垫料材料的鞋盒式笼具中。 
标准小鼠笼具提供75平方英寸的底面积，可容纳最多4-5只成年小鼠，具体数量取决于品系、性别和相容性。 
而大鼠笼具面积为142平方英寸，可容纳最多2只成年大鼠，&#160;具体数量取决于品系和相容性。饲养条件还应允许大鼠表现出正常姿势，包括直立行为。&#160; 
静态笼具通常配有金属丝网盖，笼盖上方加装过滤材料作为罩帽。独立通风笼具（IVC）也配有金属丝网盖和罩帽，但它们被放置在可向笼内供气的笼架上。&#160; 
这可以减少笼具更换频率，相较于静态笼具，可能对免疫缺陷动物更有利。 
所有笼具系统均设有饲料和供水装置。饲料可通过笼内专用食槽提供，或放置在金属丝网盖的特定区域。饲料放置位置应避免被动物污染。 
水通常通过安装在笼具顶部的饮水瓶供应，或通过动物笼具内置的自动饮水阀提供。&#160; 
对于饮水阀选项，当笼具安装到笼架上时，水通过连接至中央供水系统的自动阀门系统输送，该系统设计用于满足整个动物设施中动物的饮水需求。 
《实验动物护理与使用指南》建议笼具组件应定期消毒，通常约为每两周一次。&#160; 
某些笼具和配件可能需要更频繁更换，具体取决于 enclosure 内的气味和氨浓度水平。 
适当的饲料和供水对动物护理至关重要。市面上有多种商业饲料，其蛋白质、碳水化合物和脂肪成分各不相同。 
饲料成分可能因物种、品系和研究需求而异。对于免疫缺陷动物，饲料通常根据机构指南以灭菌形式提供。 
水应以安全且适合动物的形式提供，并根据机构指南进行处理或灭菌。 
标准环境条件对于维持动物福利同样至关重要。 
在笼具层面，除非有科学依据支持单只饲养，或某只动物与其他所有个体均不相容，否则应实行群养。&#160; 
通过提供纸屋和筑巢材料来丰富环境，可使动物表现出物种特异性行为（如筑巢和挖掘），从而降低应激水平，提高整体福利。&#160; 
筑巢材料还提供了带有气味线索的熟悉睡眠区域，有助于在同一笼具中饲养多只雄性小鼠。&#160; 
如前所述，在更换笼具时将筑巢区域转移至清洁笼具，有助于减少攻击行为，尤其是在雄性小鼠中，因为动物被引入新环境时更容易发生冲突。&#160; 
在房间层面，根据机构指南，小鼠和大鼠的室温通常维持在68至79°F之间。房间湿度应保持在30%-70%，因为较低湿度可能导致一种称为“环尾症”的疾病。第三个房间参数是光照，包括光照强度和明暗周期。&#160; 
通常，动物房设置为12小时光照/12小时黑暗循环。光照强度应根据房间内的活动情况进行调节，并在无人时维持适合该物种和品系的水平。&#160; 
最后，房间内的气流也应严格控制。通风系统应根据机构标准提供适当的每小时换气次数，以帮助减少动物房内的异味和微生物负荷。 
最后，让我们看看研究人员如何在实验中应用有关实验动物饲养、饮食和环境偏好的知识。&#160; 
如前所述，实验动物通常表现出筑巢行为，这种行为可降低应激水平，研究人员已将其作为动物福利的指标，因为它与较低的应激相关，可作为动物整体福祉的反映。这种行为可能受到环境条件（如环境温度）的影响，突显了维持适当饲养条件以支持动物福利的重要性。 
您刚刚观看了JoVE关于小鼠和大鼠基本护理程序的介绍。现在您应更好地理解了为确保这些动物的环境和操作不会对其健康造成伤害所应采取的措施，同时也了解了研究人员如何调整这些参数以实现不同的科学目标。

Education

教育

JoVE Science Education

Basic Biology

基础生物学

Lab Animal Research

实验动物研究

Rodents

啮齿类动物

基本护理程序

caring for research mice and rats

Research mice and rats need careful housing, feeding, and handling. These animals make up over 90% of the animals used for biomedical research, so their care can strongly affect experiment results. Both immunocompetent animals, which have a normal immune response, and immunocompromised animals need proper support during studies.

Some research animals have weakened immune systems and need extra steps to stay healthy. Common examples include naturally occurring immunocompromised mice and mice created through genetic engineering. The first immunocompromised mice used in research were nude mice. The BALB/c Nude, or nu, mouse was discovered in 1966 in a BALB/c colony that included mice lacking both hair and a thymus.

These athymic mice, meaning mice without a thymus, have an inhibited immune system that lacks T cells. Researchers quickly found value in nude mice for studies of microbial infections, immune deficiencies, and autoimmunity. A nude rat also exists. It is T cell deficient and has depleted cell populations in thymus-dependent areas of peripheral lymphoid organs.

Another naturally occurring immune-deficient model is the severe combined immunodeficiency, or SCID, mouse. These mice have a defect that prevents the production of functional B and T cells. Because they cannot mount an adequate immune response, they can be used as host recipients for transplants of human cells. Several genetically modified mouse strains with immune deficiencies are also available commercially.

The exact severity of immune deficiency can vary with the genetic modification. Even so, immunocompromised mice and rats are handled in similar ways. Care for both immunocompetent and immunocompromised animals includes attention to housing, diet, environmental needs, and handling. These basic steps help support the animals during research.

Caring for Research Mice and Rats

rodent handling and restraint techniques

Minimizing Stress in Mouse and Rat Handling

Mouse and rat handling can create stress, even when the procedure is brief. Cage changing and other noninvasive tasks can raise heart rate, blood pressure, and serum corticosterone levels. These changes may last for several hours. Restraint for injections and blood withdrawal can also affect the animals and may influence scientific data. Because of this, proper training is needed when working with mice and rats. The goal is to reduce the effect of handling on the animals as much as possible. <br...

basic care procedures

Research mice and rats need careful housing, feeding, and handling. These animals make up over 90% of the animals used for biomedical research, so their care can strongly affect experiment results. Both immunocompetent animals, which have a normal immune response, and immunocompromised animals need proper support during studies. Some research animals have weakened immune systems and need extra steps to stay healthy. Common examples include naturally occurring immunocompromised mice and mice...

fundamentals of breeding and weaning

Mouse and Rat Breeding Methods

Mouse and rat breeding methods are used in biomedical research to supply animals for laboratory studies. Many research facilities buy mice from commercial breeders, but some also breed mice and rats in-house. In-house breeding can reduce costs and give researchers more options for their studies. Breeding animals in the facility also lets researchers manage genetics and timing. They can plan pregnancies to match research needs and work with embryos and newborns when needed. Mice and rats can be...

rodent identification i

Mice and Rats: Ear Tags and Punch Codes

Proper identification of laboratory mice and rats is important in biomedical research. The right animal must be used for each procedure and for data collection. Clear identification helps keep research records accurate and reliable. This page focuses on permanent identification methods for mice and rats. These methods include ear tags, ear punch codes, microchip implantation, tail tattoos for adult mice, and toe tattoos for neonates. Temporary methods such as dyes and marking pens can also be...

rodent identification ii

Rodent ID Methods for Accurate Records

Accurate rodent identification supports reliable animal records and data collection. Research animal records may include simple cage cards or a detailed database with full information on each animal. Individual identification is the key part of keeping those records correct. Mice and rats can be identified by several methods. These include tattooing, microchip placement, and temporary identification methods. Each method serves a different need in research animal management. The procedure also...

compound administration i

Rodent Injection Routes and Restraint

Rodent injection routes and restraint methods are key parts of compound administration in mice and rats. When a substance must be injected into an animal, the delivery route and the amount of compound must be chosen with care. The right choice helps match the dose to the protocol. Several factors guide the route of administration. These include the pH of the solution, the volume needed for the desired dose, and the viscosity of the solution. Viscosity means how thick or resistant to flow a...

compound administration ii

Choosing the Right Route for Compound Delivery

Compound delivery is a key part of many animal studies. The route used to give the compound can change how it is absorbed. Careful planning helps make sure the compound is delivered correctly. The substance itself also matters when a route is chosen. Its pH, viscosity, and concentration can all affect which method is best. These properties help guide the choice of administration route in a study.

compound administration iii

Specialized Injection Routes in Mice and Rats

Specialized injection routes in mice and rats are sometimes used when standard compound administration methods are not enough. Some study protocols call for less common routes such as intradermal, intranasal, and intracranial injections. These methods are used in laboratory animals and require careful technique. Intradermal injections place a compound into the skin. Intranasal injections deliver a compound through the nose. Intracranial injections are given into the brain. Because these...

compound administration iv

Specialized Injection Routes in Rodents

Specialized injection routes in laboratory mice and rats include intracardiac, footpad, and retro-orbital administration. These methods are used when a protocol calls for a route that is less common than standard compound delivery methods. Each route requires specialized training to perform correctly. Intracardiac injections deliver into the heart, footpad injections target the paw area, and retro-orbital injections are given around the eye region. Because these procedures are more technical,...

blood withdrawal i

Rodent Blood Collection Methods

Blood collection in mice and rats is a common part of research studies. The method used depends on how much blood is needed, how often samples must be taken, the animal's health, and the technician's skill level. This topic includes three blood withdrawal methods: retro-orbital sinus bleeds, initial tail snip bleeds, and intracardiac bleeds. Each method requires general anesthesia, which means the animal is made unconscious before the procedure begins.

blood withdrawal ii

Rodent Blood Sampling Methods

Blood collection from mice and rats can be done with several methods. The choice depends on the restraint needed, how invasive the procedure is, and whether a general anesthetic is required. These factors help determine which method is best for a given analysis. One older method uses the retro-orbital sinus cavity, which is located behind the eye. This approach has been debated because it may cause tissue damage or even blindness. For that reason, facial vein and submandibular vein bleeding...

anesthesia induction and maintenance

Laboratory Anesthesia and Pain Control

Laboratory anesthesia and pain control are important parts of veterinary care for research animals. The Guide for the Care and Use of Laboratory Animals says that pain assessment and pain relief must be part of that care. Anesthesia means the loss of feeling or sensation.

considerations for rodent surgery 

Aseptic Steps in Rodent Survival Surgery

Aseptic technique is essential for rodent survival surgery. It is used to keep the surgical site as clean as possible and to reduce contamination during the procedure. This approach includes patient preparation, surgeon preparation, and sterilization of instruments and other supplies. It also depends on a clean, controlled environment. Careful planning before surgery helps set up these steps for success. During the operation, animals need close monitoring. After the surgery, postoperative...

diagnostic necropsy and tissue harvest

Rat Necropsy for Tissue Collection

Rat necropsy is a key step for collecting organs and tissues at the end of many animal studies. These final samples are used for data collection time points and later testing. Because the samples are used for analysis, the way they are taken can affect sample quality. Careful collection methods help preserve the organs and tissues for testing. The method of euthanasia, or the procedure used to humanely end the animal's life, can also affect sample quality. This article outlines proper necropsy...

sterile tissue harvest

Aseptic Organ Collection in Rats and Mice

Aseptic organ collection in rats and mice is used to keep harvested tissues free from contamination. The process is important when tissues will be used for cell and tissue cultures. It also supports later protein and RNA analysis, as well as metabolic profiling of tissues. The transcript connects this work to the 3 R's, which were introduced in 1959 by W.M.S. Russell and R.L. Burch in The Principles of Humane Experimental Technique. The 3 R's are replacement, reduction, and refinement in the...

early intervention and pain management

早期干预与疼痛管理

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作均须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），且必须由经过培训的人员执行。  监测动物疼痛与痛苦的迹象 识别疼痛的早期征象对于符合伦理的动物研究至关重要。通常通过反映动物整体健康状况的行为、生理和物理参数来对动物进行常规监测。这些参数包括体重变化，持续性体重下降或未能维持预期的体重增长可能提示存在疼痛、疾病或慢性应激。体重评估需结合动物自身的基线数据及预期生长模式，而非仅依据单一数值。其他指标还包括筑巢行为，筑巢不良提示可能存在不适；以及水合状态，通常通过皮肤弹性或黏膜外观进行评估。例如，实验操作后停止理毛、体重下降或忽视筑巢的小鼠可能正处于疼痛状态。活动量减少、摄食或饮水模式改变以及社交互动减少等其他表现也提示动物福利受到损害。 使用小鼠面部表情量表评估疼痛 面部表情评分提供了一种更为敏感的疼痛评估方法。小鼠疼痛面容量表（Grimace...

humane euthanasia and confirmation of death in rodents

啮齿类动物的人道安乐死与死亡确认

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 啮齿类动物的仁慈终点是预先定义的临床、行为或生理指标，用于提示动物正在经历显著的疼痛、痛苦或健康状况下降。当观察到这些体征时，需及时采取干预措施，以最大程度减轻动物痛苦并保障其福利。  化学安乐死 该操作通常通过注射给予过量的批准麻醉剂来开始，具体选择取决于物种和研究方案。注射用麻醉剂（如戊巴比妥钠）可迅速抑制中枢神经系统活性。给药后，动物将失去意识和反射活动。深度麻醉会进一步发展为呼吸抑制，随后心脏和脑功能停止。在诱导前，轻柔操作和适当固定对于最大限度减少动物恐惧和应激至关重要。 吸入剂使用方法 此外，也可使用吸入性麻醉剂实施安乐死。将动物置于受控环境中，通过诱导室或面罩输送麻醉蒸气。诸如异氟烷或七氟烷等试剂可在动物感知疼痛前诱导其失去意识。该方法通过逐步镇静并尽量减少操作，从而降低动物的痛苦。<br...

habituation and positive reinforcement for rodent handling

啮齿类动物操作中的习惯化与正向强化

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经动物护理和使用委员会（IACUC）批准。所有操作必须遵守“3R”原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 习惯化和正向强化是有助于减少啮齿类动物在常规操作和实验过程中应激的优化策略。这些方法可改善动物福利，促进动物自愿配合，并减少可能影响研究结果的与应激相关的效应。 习惯化 习惯化是一种非联合型学习形式，指动物对重复出现的无威胁性刺激的反应随时间推移而逐渐减弱。通过反复接触操作人员、操作工具或实验程序环境，啮齿类动物会逐渐熟悉这些原本可能引发恐惧或回避行为的经历。习惯化训练应短暂、一致，并逐步引入，以使动物能够按照自身的节奏适应。 正向强化<br...

breeding management in rodent studies

啮齿类动物研究中的繁殖管理

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经机构动物护理和使用委员会（IACUC）批准。所有操作须遵守“3R”原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 繁殖管理通过减少不必要的动物生产，确保仅产生研究所需的动物数量，从而支持“3R”原则。有效的繁殖策略有助于减少过剩动物，提高动物资源的利用效率，同时保证科学目标的实现。 影响繁殖成功率的因素 育种计划应考虑影响种群繁殖效率的品系特异性及生物学变量，包括交配成功率、每窝产仔数、仔鼠存活率、基因型频率、性别分布、生育力以及繁殖寿命。准确预测这些变量有助于研究人员获得所需数量的实验动物，同时避免过度繁殖。 育种计算<br...

transport and acclimatization of rodents for research

实验用啮齿类动物的运输与适应性驯养

此处描述的所有动物实验操作必须遵循机构动物伦理指南，并经动物护理和使用委员会（IACUC）批准。所有操作须遵守“3R”原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 为科研目的运输啮齿类动物时，需采取相应措施，以尽量减少运输过程中的动物应激并保障动物福利，从而降低对实验结果的干扰。运输笼具应提供充足的通风、垫料、食物以及水合物来源（如凝胶补液包）。小鼠应轻柔操作，放入笼内时避免过度拥挤，以减少应激、攻击行为及受伤风险。笼具应牢固关闭，标明“活体动物”及相关运输信息，并覆盖透气材料，以减少外界刺激，同时确保良好的通风和温度控制。 运输与应激减轻 动物应通过机构指定的路线运输，避免经过公共区域和公共交通系统。公共区域会使动物暴露于过度的噪音、振动、陌生气味、温度波动和人类活动之中，这些因素均可能引发应激反应。运输过程中，应保持笼具直立、水平并固定稳妥，以防止不必要的移动和损伤，从而进一步降低与运输相关的应激。 笼具消毒与动物转移<br...

environmental enrichment for rodents

啮齿类动物的环境富集

此处所述的所有动物实验操作必须遵循机构动物伦理指南，并经IACUC批准。所有操作须遵守3R原则——替代（Replacement）、减少（Reduction）和优化（Refinement），并由经过培训的人员执行。 环境丰容是指采用各种物品和方法来促进实验啮齿类动物的自然行为，改善其心理福祉，并提升动物福利。环境丰容应根据啮齿类动物的物种、品系、年龄、性别及研究设计进行定制，并依照机构的动物护理规程提供。 小鼠的环境富集 筑巢材料与隧道 对于小鼠而言，筑巢材料是最重要的环境丰富化资源之一。垫料和筑巢材料，如木丝、木屑、撕碎的纸张、纸条或巢垫块，均能强烈激发雄性和雌性小鼠的筑巢行为。筑巢行为还可作为健康和福利状况的重要指标，因为处于应激、患病或热应激状态的小鼠可能无法构建充分的巢穴。在笼内添加藏身处，例如隧道，可为小鼠提供安全的躲藏、休息和探索空间。 环境丰富化区域与啃咬物体<br...

rodents

Learn how research mice and rats are housed, fed, and handled, including nude and SCID models used in studies of infection, immunity, and transplants.

Caring for Research Mice and Rats | JoVE K12

HS-LS1-3.

Kay Stewart

Valerie A. Schroeder

University of Notre Dame

Overview

Unpacking and Cage Changing Procedures

Housing

Diet

Environment

Applications

Summary

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

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Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

Visualizing Onion and Cheek Cells
ExpandImmediately before the experiment, wash and peel onion bulbs for the class.
Remove the entire brown outer skin and ...

Visualizing Onion and Human Cells
ExpandIn this experiment you will prepare different types of cells from a plant and animal, onion and human ...

What are Cells?

Cell Diversity

The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term &#34;cell&#34; based on the ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

The Central Dogma

The DNA Helix

Nucleic Acids

DNA as a Genetic Template

Structure of a Gene

A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the ...

Chromosome Structure

Base-pairing and DNA Repair

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Translation

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Protein and Protein Structures

Proteins: From Genes to Degradation

From DNA to Protein

The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of ...

Protein Folding

Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to ...

An Overview of Gene Expression

Gene expression is the complex process where a cell uses its genetic information to make functional products. This process is regulated at multiple ...

an-introduction-to-caenorhabditis-elegans

An Introduction to Caenorhabditis elegans

Caenorhabditis elegans is a microscopic, soil-dwelling roundworm that has been powerfully used as a model organism since the early 1970&rsquo;s.  It was ...

An Overview of Genetic Analysis

An organism&#8217;s physical traits, or phenotype, are a product of its genotype, which is the combination of alleles (gene variants) inherited from its ...

An Introduction to Cell Death

Necrosis, apoptosis, and autophagic cell death are all manners in which cells can die, and these mechanisms can be induced by different stimuli, such as ...

An Overview of Genetic Engineering

Genetic engineering &#8211; the process of purposefully altering an organism&#8217;s DNA &#8211; has been used to create powerful research tools and model ...

An Introduction to Cell Division

Cell division is the process by which a parent cell divides and gives rise to two or more daughter cells. It is a means of reproduction for single-cell ...

An Overview of Genetics and Disease

Many human diseases are associated with mutations or variations in genetic sequences. Some of these genetic variants are heritable, passed down from ...

an-introduction-to-cellular-and-molecular-neuroscience

An Introduction to Cellular and Molecular Neuroscience

Cellular and molecular neuroscience is one of the newest and fastest growing subdisciplines in neuroscience. By investigating the influences of genes, ...

Annexin V and Propidium Iodide Labeling

Staining with annexin V and propidium iodide (PI) provides researchers with a way to identify different types of cell death&#8212;either necrosis or ...

an-introduction-to-developmental-genetics

An Introduction to Developmental Genetics

Development is the complex process through which a single-celled embryo transforms into a multicellular organism. Developmental processes are guided by ...

Bacterial Transformation: Electroporation

The term &#x201C;transformation&#x201D; refers cellular ingestion of foreign DNA.  In nature, transformation can occur in certain types of bacteria.  In ...

an-introduction-to-molecular-developmental-biology

An Introduction to Molecular Developmental Biology

Molecular signals play a major role in the complex processes occurring during embryonic development. These signals regulate activities such as cell ...

bacterial-transformation-the-heat-shock-method

Bacterial Transformation: The Heat Shock Method

Transformation is the process that occurs when a cell ingests foreign DNA from its surroundings. Transformation can occur in nature in certain types of ...

an-introduction-to-saccharomyces-cerevisiae

An Introduction to Saccharomyces cerevisiae

Saccharomyces cerevisiae (commonly known as baker&rsquo;s yeast) is a single-celled eukaryote that is frequently used in scientific research.  S. ...

Cell Cycle Analysis

Cell cycle refers to the set of events through which a cell grows, replicates its genome, and ultimately divides into two daughter cells through the ...

An Introduction to Transfection

Transfection is the process of inserting genetic material, such as DNA and double stranded RNA, into mammalian cells. The insertion of DNA into a cell ...

Chromatin Immunoprecipitation

Histones are proteins that help organize DNA in eukaryotic nuclei by serving as &#8220;scaffolds&#8221; around which DNA can be wrapped, forming a complex ...

An Overview of Epigenetics

Since the early days of genetics research, scientists have noted certain heritable phenotypic differences that are not due to differences in the ...

community-dna-extraction-from-bacterial-colonies

Community DNA Extraction from Bacterial Colonies

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Luisa Ikner
Traditional methods of analysis ...

Cytogenetics

Cytogenetics is the field of study devoted to chromosomes, and involves the direct observation of a cell&#8217;s chromosomal number and structure, ...

embryonic-stem-cell-culture-and-differentiation

Embryonic Stem Cell Culture and Differentiation

Culturing embryonic stem (ES) cells requires conditions that maintain these cells in an undifferentiated state to preserve their capacity for self-renewal ...

DNA Gel Electrophoresis

DNA gel electrophoresis is a technique used for the detection and separation of DNA molecules. An electric field is applied to a gel matrix comprised of ...

Enzyme Assays and Kinetics

Enzyme kinetics describes the catalytic effects of enzymes, which are biomolecules that facilitate chemical reactions necessary for living organisms. ...

DNA Ligation Reactions

In molecular biology, ligation refers to the joining of two DNA fragments through the formation of a phosphodiester bond.  An enzyme known as a ligase ...

explant-culture-for-developmental-studies

Explant Culture for Developmental Studies

Explant culture is a technique in which living cells or tissues are removed from an embryo for continued development outside of the organism. This ex vivo ...

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

HS-LS1-1.

Caring for Research Mice and Rats

Description

Transcript

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