Practical Guide

如何平衡离心力与剪切力？降剪增离的核心方法

How to Balance Centrifugal Force and Shear Force

在前两篇中，我们搞懂了离心力（分离的动力）和剪切力（样品的敌人）的核心理论——离心力不够，分离不彻底；剪切力太强，样品被破坏。对实验和生产来说，最关键的需求是：在保证足够离心力的同时，尽可能降低剪切力。

In the first two articles, we covered the core theories of centrifugal force (the driving force for separation) and shear force (the enemy of samples). Insufficient RCF means incomplete separation; excessive shear force means damaged samples. The key challenge is: maintaining sufficient centrifugal force while minimizing shear force.

今天这篇，结合前两篇的理论，给大家带来实操指南，详细讲解"降低剪切力""增加离心力"的具体方法，兼顾理论与落地，新手也能轻松掌握。

This article combines the theories from Parts I and II into a practical guide, detailing specific methods to "reduce shear force" and "increase centrifugal force" — balancing theory with hands-on application, accessible even for beginners.

Section 1: How to Reduce Shear Force (3 Core Strategies)

降低剪切力的核心逻辑：减少样品液体的"晃动、冲击、摩擦"，让流体流动更平稳。可从硬件、操作、样品三个维度入手：

The core logic of reducing shear force: minimize "agitation, impact, and friction" of the sample liquid, ensuring smoother fluid flow. This can be approached from three dimensions: hardware, operation, and sample preparation.

①硬件选型：从根源减少剪切力（最关键）

Hardware Selection: The Most Fundamental Approach

• 优先选水平转子：相比角转子、垂直转子，水平转子样品流动更平稳，无斜向冲击，剪切力最低。

Prioritize swing-out (horizontal) rotors: compared to fixed-angle or vertical rotors, swing-out rotors provide smoother sample flow with no diagonal impact — lowest shear force.

• 选低剪切机型：密封底部进料、空心轴、碟片式或连续流离心机，流道光滑、无死角，减少液体冲击和摩擦。

Choose low-shear centrifuge types: sealed bottom-feed, hollow-shaft, disc, or continuous-flow centrifuges feature smooth, dead-end-free flow channels that minimize liquid impact and friction.

• 选光滑流道转子：转子内壁和离心管无毛刺、无死角，避免液体在局部产生湍流和摩擦。

Select rotors with smooth flow channels: rotor inner walls and centrifuge tubes free of burrs and dead zones prevent localized turbulence and friction.

②操作参数：优化细节，减少冲击  

Operating Parameters: Fine-Tune to Minimize Impact

• 合理降低转速：在满足样品分离需求的前提下，尽量降低转速（转速降低，湍流减弱，剪切力同步降低）。

Reasonably reduce rotation speed: as long as separation requirements are met, lower speed reduces turbulence and shear force proportionally.

• 缩短离心时间：减少样品在离心场中的暴露时间，降低剪切力的累积损伤。

Shorten centrifugation time: reducing exposure time in the centrifugal field lowers cumulative shear force damage.

• 严格控温：适当降低温度，可增加缓冲液粘度，减少湍流，降低剪切力，同时保护样品活性。

Strict temperature control: lower temperature increases buffer viscosity, reduces turbulence, decreases shear force, and simultaneously protects sample bioactivity.

③样品与流体优化：减少摩擦  

Sample and Fluid Optimization: Reduce Friction

• 使用高粘度缓冲液：粘度增加能起到"阻尼"作用，减少液体内部的速度差异和湍流，降低剪切力。

Use high-viscosity buffer: increased viscosity acts as a "damper," reducing internal velocity gradients and turbulence, lowering shear force.

• 控制进料流速（连续流离心）：降低进料流速，使液体呈"层流"状态，避免湍流产生。

Control feed flow rate (for continuous-flow centrifugation): lower flow rate maintains laminar flow conditions, preventing turbulence.

• 避免气泡和泡沫：气泡破裂时会产生局部强剪切力，离心前需去除样品中的气泡，操作时避免剧烈晃动。

Avoid bubbles and foam: bubble collapse generates localized high shear forces. Degas samples before centrifugation and avoid vigorous agitation during handling.

Section 2: How to Increase Centrifugal Force

结合第一篇的公式（RCF ∝ r × N²），增加离心力的核心是"放大转速和半径的影响"，优先选高效方法，分3类：

Based on the formula from Part I (RCF ∝ r × N²), increasing centrifugal force means "amplifying the effects of speed and radius." Choose the most efficient approach from 3 categories:

①优先提高转速（最高效，平方效应） 

Increase Speed First (Most Efficient — Square Effect)

转速是影响离心力的核心因素，转速翻倍，离心力翻4倍。具体可通过：选用高转速离心机（无刷/磁悬浮电机，运行平稳）、选用轻量化转子（钛合金/碳纤维，能承受更高转速）、配备真空/风冷系统（降低风阻和温升，避免转速受限）。

Speed is the primary factor affecting centrifugal force — doubling speed quadruples RCF. Options include: selecting high-speed centrifuges (brushless/maglev motors for stable operation); using lightweight rotors (titanium alloy/carbon fiber for higher speed tolerance); and equipping vacuum/air-cooling systems (reduce air resistance and heat buildup to avoid speed limitations).

②增大有效半径（线性效应，辅助提升）  

Increase Effective Radius (Linear Effect — Secondary)

• 选用大直径转子：转子直径越大，样品的有效旋转半径越大，离心力同步增加； • 选用长吊篮/长离心管：让样品放置位置离旋转中心更远，增加有效半径，提升离心力。

Select larger diameter rotors: greater rotor diameter increases effective radius and centrifugal force proportionally. • Use longer buckets/tubes: placing samples farther from the rotation center increases effective radius and thus RCF.

③工艺辅助（间接提升分离效果）  

Process Aids (Indirect Enhancement of Separation Efficiency)

• 密度梯度离心：通过添加密度梯度介质，放大不同样品成分的沉降差异，无需过高离心力就能实现彻底分离； • 加入助沉剂（如PEG、蔗糖等）：增加样品颗粒的有效质量，加速沉降，降低对离心力的要求； • 温控降粘：适当升温（针对非敏感样品），降低缓冲液粘度，提升沉降速度，间接减少离心力需求。

Density gradient centrifugation: adding density gradient media amplifies sedimentation differences between components, enabling thorough separation without excessively high RCF. • Add sedimentation aids (e.g., PEG, sucrose): increase effective particle mass to accelerate sedimentation and reduce RCF requirements. • Temperature-controlled viscosity reduction: gentle warming (for non-sensitive samples) reduces buffer viscosity, improving sedimentation speed and indirectly reducing RCF needs.

Section 3: Core Summary — Key Logic for Balancing RCF and Shear Force

Summary

离心力由"转速²×有效半径"决定，提升离心力优先提转速，再增大半径；剪切力由"转子设计、流体状态、操作参数"决定，降低剪切力优先选水平转子、慢加减速、优化样品体系。最优方案：根据样品类型（敏感/普通），选择"低剪切转子+合适转速+慢加减速"，既保证分离彻底，又保护样品活性。

Centrifugal force is determined by "speed² × effective radius" — to increase RCF, prioritize speed, then radius. Shear force is governed by rotor design, fluid state, and operating parameters — to reduce it, prioritize swing-out rotors, slow ramp rates, and sample system optimization. The optimal approach: based on sample sensitivity, select "low-shear rotor + appropriate speed + slow ramp" to ensure thorough separation while protecting sample bioactivity.

收藏这篇实操指南，离心实验少踩坑！有具体样品（细胞/蛋白/病毒）的离心需求，可留言咨询～

BIO-CHEM T6R 低速冷冻离心机

T6R 低速冷冻离心机  |  T6R Low-Speed Refrigerated Centrifuge

产品简介| Product Overview

T6R低速冷冻离心机是渤程重磅推出的大容量台式冷冻离心机，最大容量可达4×750ml。凭借更大的转子半径（最大RCF 6842×g）、进口制冷系统和多重安全防护，T6R完美兼顾"高离心力"与"低剪切力"的平衡需求，是生物科研、临床检验、大规模细胞处理的理想选择。

The T6R Low-Speed Refrigerated Centrifuge is a large-capacity benchtop refrigerated centrifuge from BIO-CHEM Biotech. With a maximum capacity of 4×750ml, a larger rotor radius (max RCF 6,842×g), imported refrigeration system, and comprehensive safety protections, the T6R perfectly balances "high centrifugal force" and "low shear force" — the ideal choice for biological research, clinical diagnostics, and large-scale cell processing.

核心特点| Key Features

① 7英寸彩色高灵敏度电阻式触摸屏，手套操作，用户界面直观，操作便捷。

7-inch color high-sensitivity resistive touch screen with glove-operable interface for intuitive, convenient operation.

② MCU控制无刷电机，运行稳定，噪音低（<60dB），转速精确（±1%），无碳粉污染。

MCU-controlled brushless motor: stable operation, low noise (<60dB), precise speed control (±1%), no carbon dust contamination.

③ 双重安全锁定机制（结构自锁+电动锁定），配备门传感器检测和盖子打开报警系统。

Dual-lock safety mechanism (structural + motorized locking), with door sensor detection and open-lid alarm.

④ 进口Tecumseh压缩机（美国制造），采用环保制冷剂，持续制冷温度稳定性±1℃。

Imported Tecumseh compressor (USA-made) with eco-friendly refrigerant; continuous refrigeration with ±1°C temperature stability.

⑤ 快速预冷：从24℃预冷至4℃仅需5–7分钟，大幅节省实验准备时间。

Rapid pre-cooling: from 24°C to 4°C in just 5–7 minutes, significantly saving experiment preparation time.

⑥ 专利待批防结露设计，防止轴承腐蚀，使用寿命可延长至50,000次循环。

Patent-pending anti-condensation design prevents bearing corrosion, extending service life to 50,000+ cycles.

⑦ 离心结束后可编程自动解锁，简化样本处理程序。

Programmable auto-unlock after centrifugation; streamlines sample handling workflow.

⑧ 内腔与蒸汽接触的所有内部表面均采用304不锈钢，耐腐蚀耐用。

All internal surfaces in contact with vapors made of 304 stainless steel for corrosion resistance and durability.

⑨ 实时转速-离心力切换，可直接输入离心力，系统故障诊断配有声音/视觉警报。

Real-time RPM/RCF switching with direct RCF input; system diagnostics with audio/visual alarms.

⑩ 综合安全协议：盖子联锁、错误检测、超速保护（≤20%容差）、温度控制（±2℃）、动态不平衡补偿。

Comprehensive safety protocols: lid interlock, error detection, overspeed protection (≤20% tolerance), temperature control (±2°C), and dynamic imbalance compensation.

⑪ 可调加速/减速曲线（10–30秒），具备可编程梯度离心功能，优化沉淀物形成。

Adjustable acceleration/deceleration curves (10–30 sec) with programmable gradient centrifugation to optimize pellet formation.

⑫ 水平转子支持对称≤10g、对角线<200g的不平衡混合装载；支持BLE 5.0连接的可升级端口。

Horizontal rotor supports unbalanced mixed loading (symmetric ≤10g, diagonal <200g); upgradeable port supporting BLE 5.0 connectivity.

产品参数| Technical Specifications

T6R 转子配置表  |  T6R Rotor Configuration

可根据客户需求定制转子和适配器| Rotors and adapters can be customized per customer requirements