Ever wondered how scientists study the tiny parts inside cells?...
Biology75 views·Updated 17 Aug 2026·2 pagesCell Fractionation Explained
libby griffiths@libbygriffiths_azle
1
of 2
Cell Fractionation Basics
Want to study what's inside a cell? You've got to get those organelles out first! Cell fractionation is basically the process of breaking cells apart and then sorting out all the different bits inside.
Before you start smashing cells, you need to prep them properly. The tissue goes into a special solution that's cold (to stop enzymes from destroying everything), has the same water potential as the tissue (so organelles don't explode or shrivel up), and is buffered (keeping the pH stable so nothing gets damaged).
Next comes homogenisation - think of it like putting cells in a blender called a homogeniser. This releases all the organelles from their cellular prisons. The resulting mixture (called homogenate) gets filtered to remove any leftover cell debris and chunks.
Key Point: The three conditions (cold, isotonic, buffered) are absolutely crucial - mess these up and your organelles will be ruined before you even start!
Finally, centrifugation separates the organelles based on their properties. There are two main types: ultracentrifugation (sorts by weight) and density gradient centrifugation (sorts by density). Once separated, scientists can study each organelle individually.
2
of 2
Ultracentrifugation Process
Ultracentrifugation works like a super-powered washing machine that sorts organelles by weight. The heavier something is, the faster it gets flung to the bottom when spun around.
Here's how it works step by step. First, you break up the cells and prepare your homogenate in that special cold, isotonic, buffered solution. Then you transfer everything to centrifuge tubes for the spinning process.
The magic happens in stages. Start with low speed for a short time - the heaviest organelles (like nuclei) form a pellet at the bottom. The liquid on top (called the supernatant) contains everything else. Remove this supernatant and spin it faster for longer - now the next heaviest organelles settle out.
Remember: Heavy organelles = low speed, short time. Light organelles = high speed, long time.
You keep repeating this process, increasing the speed and time each round. Each spin separates out progressively lighter organelles until you've got neat, separate samples of each type. It's like having different sized sieves that catch different components!
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar content
BiologyMost popular content in Biology
9BiologyA-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
1215,108699
BiologyAQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
109,097310
BiologyBiology P2: Evolution & Adaptation
Explore key concepts in AQA GCSE Biology P2, focusing on evolution, natural selection, genetic engineering, and adaptations in organisms. This summary covers essential topics such as DNA structure, speciation, and the impact of environmental changes on biodiversity. Ideal for exam preparation and understanding complex biological processes.
111,24122
BiologyA-Level Biology Year 2 Overview
Comprehensive study notes covering key concepts in AQA A-Level Biology Year 2, including neuronal communication, genetic modification, nutrient cycles, and hormonal control. This resource is designed to aid understanding of complex topics such as action potentials, photosynthesis, and speciation. Ideal for exam preparation and revision.
125,987306
Biologybiology paper 1
all notes
112,59438
BiologyBiology Paper 1 Overview
Comprehensive study notes covering key concepts in cellular biology, human digestion, respiration, photosynthesis, and the circulatory system. This resource includes detailed explanations of cell structures, enzyme functions, nutrient absorption, and the impact of environmental factors on biological processes. Ideal for students preparing for Biology Paper 1 exams.
1115,423389
BiologyBiology paper 1 foundation & higher
Pages from the revision guide summarised in a set of words and a brief explanation
101,44518
BiologyKS3 Biology
KS3 Biology revision document.
761968
BiologyPaper 2 chemistry mindmaps
Condesnsed aqa triple higher
958110
Most popular content
9
SociologyComprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
1251,7491,403
SociologySociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
1231,590848
SociologySociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
1273,9872,306
SociologySociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
12103,1443,044
SociologyCrime and Deviance AQA A-level sociology
AQA A-level crime and deviance topic notes
1289019
ChemistryChemistry paper 2
Chem paper 2 notes
1173414
BiologyA-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
1215,108699
BiologyAQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
109,097310
BiologyBiology P2: Evolution & Adaptation
Explore key concepts in AQA GCSE Biology P2, focusing on evolution, natural selection, genetic engineering, and adaptations in organisms. This summary covers essential topics such as DNA structure, speciation, and the impact of environmental changes on biodiversity. Ideal for exam preparation and understanding complex biological processes.
111,24122
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user
Biology75 views·Updated 17 Aug 2026·2 pagesCell Fractionation Explained
libby griffiths@libbygriffiths_azle
Ever wondered how scientists study the tiny parts inside cells? Cell fractionation is the clever technique that lets us break open cells and separate their different components, like splitting up a complex machine to see how each part works.
1
of 2
Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Cell Fractionation Basics
Want to study what's inside a cell? You've got to get those organelles out first! Cell fractionation is basically the process of breaking cells apart and then sorting out all the different bits inside.
Before you start smashing cells, you need to prep them properly. The tissue goes into a special solution that's cold (to stop enzymes from destroying everything), has the same water potential as the tissue (so organelles don't explode or shrivel up), and is buffered (keeping the pH stable so nothing gets damaged).
Next comes homogenisation - think of it like putting cells in a blender called a homogeniser. This releases all the organelles from their cellular prisons. The resulting mixture (called homogenate) gets filtered to remove any leftover cell debris and chunks.
Key Point: The three conditions (cold, isotonic, buffered) are absolutely crucial - mess these up and your organelles will be ruined before you even start!
Finally, centrifugation separates the organelles based on their properties. There are two main types: ultracentrifugation (sorts by weight) and density gradient centrifugation (sorts by density). Once separated, scientists can study each organelle individually.
2
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ultracentrifugation Process
Ultracentrifugation works like a super-powered washing machine that sorts organelles by weight. The heavier something is, the faster it gets flung to the bottom when spun around.
Here's how it works step by step. First, you break up the cells and prepare your homogenate in that special cold, isotonic, buffered solution. Then you transfer everything to centrifuge tubes for the spinning process.
The magic happens in stages. Start with low speed for a short time - the heaviest organelles (like nuclei) form a pellet at the bottom. The liquid on top (called the supernatant) contains everything else. Remove this supernatant and spin it faster for longer - now the next heaviest organelles settle out.
Remember: Heavy organelles = low speed, short time. Light organelles = high speed, long time.
You keep repeating this process, increasing the speed and time each round. Each spin separates out progressively lighter organelles until you've got neat, separate samples of each type. It's like having different sized sieves that catch different components!
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar content
Most popular content in Biology
9BiologyA-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
1215,108699
BiologyAQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
109,097310
BiologyBiology P2: Evolution & Adaptation
Explore key concepts in AQA GCSE Biology P2, focusing on evolution, natural selection, genetic engineering, and adaptations in organisms. This summary covers essential topics such as DNA structure, speciation, and the impact of environmental changes on biodiversity. Ideal for exam preparation and understanding complex biological processes.
111,24122
BiologyA-Level Biology Year 2 Overview
Comprehensive study notes covering key concepts in AQA A-Level Biology Year 2, including neuronal communication, genetic modification, nutrient cycles, and hormonal control. This resource is designed to aid understanding of complex topics such as action potentials, photosynthesis, and speciation. Ideal for exam preparation and revision.
125,987306
Biologybiology paper 1
all notes
112,59438
BiologyBiology Paper 1 Overview
Comprehensive study notes covering key concepts in cellular biology, human digestion, respiration, photosynthesis, and the circulatory system. This resource includes detailed explanations of cell structures, enzyme functions, nutrient absorption, and the impact of environmental factors on biological processes. Ideal for students preparing for Biology Paper 1 exams.
1115,423389
BiologyBiology paper 1 foundation & higher
Pages from the revision guide summarised in a set of words and a brief explanation
101,44518
BiologyKS3 Biology
KS3 Biology revision document.
761968
BiologyPaper 2 chemistry mindmaps
Condesnsed aqa triple higher
958110
Most popular content
9SociologyComprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
1251,7491,403
SociologySociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
1231,590848
SociologySociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
1273,9872,306
SociologySociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
12103,1443,044
SociologyCrime and Deviance AQA A-level sociology
AQA A-level crime and deviance topic notes
1289019
ChemistryChemistry paper 2
Chem paper 2 notes
1173414
BiologyA-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
1215,108699
BiologyAQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
109,097310
BiologyBiology P2: Evolution & Adaptation
Explore key concepts in AQA GCSE Biology P2, focusing on evolution, natural selection, genetic engineering, and adaptations in organisms. This summary covers essential topics such as DNA structure, speciation, and the impact of environmental changes on biodiversity. Ideal for exam preparation and understanding complex biological processes.
111,24122
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user