Name: membrane proteins in liposome models
Uploaded: 2023-04-30T06:31:34.000Z
Duration: 7 min 5 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-LS1-3.

Reconstitution of Membrane Proteins

膜タンパク質の再構成

再構成は、元のフォームまたは関数に分離生体分子を返すプロセスです。これは、膜タンパク質は、細胞の重要な機能を有効にし、近くの脂質の動作に影響を研究するため便利です。原精製膜蛋白質の機能を研究するには、彼らは人工脂質膜にそれらを統合することによって再構成する必要があります。
このビデオは、膜タンパク質の再構成の概念と洗剤、人工の小胞に隔離された蛋白質の定款及びソリューションから洗剤の分離、脂質を用いた人工膜小胞の形成を使用して蛋白質の隔離など、関連する手順を紹介します。最後に、2 つのアプリケーションが覆われている: 膜の輸送蛋白質及び集光性タンパク質の再構成の再構成。
<div class="chapter_text" id="script_0">
再構成は、元のフォームまたは機能に分離生体分子を復元するプロセスです。このアプローチは、膜タンパク質は、多くの重要な細胞プロセスを有効にして、隣接の脂質の動作に影響を勉強するときによく使用されます。ただし、細胞環境の複雑さは、膜タンパク質機能の勉強は難しいin-situ 。タンパク質を抽出し、精製することができますが、膜なしの実際の関数を評価できません。したがって、分離膜蛋白質はリポソームなどの人工の脂質膜への統合によって再構成されたです。膜タンパク質溶解、一般的な再構成手順と生化学のいくつかのアプリケーションの原則を紹介します。
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<div class="chapter_text" id="script_1">
細胞膜は、主にリン脂質と膜タンパク質で構成されます。リン脂質二重層の脂肪酸の疎水性尾は 2 層で相互に対話しながら親水性のリン酸ヘッドが水性インテリアと、セルの外観と対話を形成します。
いくつかの膜タンパク質はのみ静電気または noncovalent 相互作用によって膜と対話します。'不可欠な蛋白質' と呼ばれる、他の人は、脂質二重層に埋め込まれます。
二層のような不可欠なタンパク質は親水性が終了し、疎水性中心があるし、疎水性相互作用によって固定されます。全体の膜にまたがる不可欠なタンパク質は、膜貫通蛋白質と呼ばれます。
これらの蛋白質と細胞膜の相互作用が強いことも、細胞を溶解分離しませんそれらです。洗剤と呼ばれる特殊な界面活性剤を使用して蛋白質を抽出します。リン脂質と同様に、洗剤は親水性のヘッドと脂溶性の尾があるし、膜を自由に入力することができます。
膜内洗剤の脂溶性のツインテールは疎水性蛋白質のコアと対話します。これは、タンパク質-脂質相互作用を混乱させる親水性の洗剤ヘッドのシェルを持つタンパク質を囲みます。
蛋白質界面活性剤複合体今簡単に膜から分離します。水溶液に可溶と人工膜の再構成の準備ができて、洗剤は複合体をつくる。
蛋白質はしばしば人工膜小胞であるリポソームの膜に再構成されました。リポソームを準備するには、乾燥脂質が水分し、小胞形成を誘導するのに興奮しています。洗剤を追加するときは、リポソーム膜に組み込まれます。
蛋白質を再構成するリポソームと可溶性タンパク質が結合され、透析または化学吸着によって、洗剤がソリューションから削除されます。タンパク質とリポソーム急速に組み立ててプロテオリポソーム、だから親水性グループのみが公開されます。タンパク質には、細胞膜で分離して調べることができます彼らと、機能します。
リポソームの膜タンパク質の再構成のプロトコルを介してタンパク質再構成の基礎を説明しましたので、これで行こう
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<div class="chapter_text" id="script_2">
膜タンパク質を分離するには、セルが分離されます。遠心分離と切れ目のない細胞が削除されます。
上清は膜をペレットを高速で遠心分離します。ペレットの再懸濁は、タンパク質を抽出する洗剤が追加されます。
残りの細胞の残骸が追加の遠心分離によって削除されます。タンパク質は、カラム ・ クロマトグラフィと培養上清より精製した集中や必要に応じてさらに精製します。
リポソームを準備するには、有機溶媒中でリン脂質の懸濁液、窒素またはアルゴンの下で乾燥させます。
リン脂質が水和反応バッファーと水和および混合物は、リポソームの作成を完了する超音波処理します。
洗剤は、蛋白質と結合されるリポソームを可溶化に追加されます。
洗剤は、ポリスチレン ビーズ、透析、または洗剤バインド列への吸着によって削除されます。結果プロテオリポソームは浄化され、その後の実験で使用する準備ができています。
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<div class="chapter_text" id="script_3">
今、あなたは、膜タンパク質の再構成手順の基本原則に精通しているが、生化学のタンパク質再構成のいくつかのアプリケーションを見てみましょう。
膜輸送タンパク質は、トランスポート メカニズムの明確な理解を得るために再構成されました。その関数の後の再構成は、ヨウ化物イオンの流出を確認しました。その後、様々 な小分子イオン チャネル阻害剤や度の存在下で輸送活動を調べた。このように、これらの小さな分子の輸送蛋白質との直接相互作用を検討する可能性が。
クロロフィルとカロテノイド結合膜タンパク質植物の光を収穫、電荷分離を促進するため、光損傷を軽減します。これらの集光性タンパク質を再構成によって、フォールディング動力学と顔料との相互作用を学ぶことができます。この手法で再構成した集光性タンパク質は、ネイティブ蛋白質に非常に同じような光学的性質を持っていた。蛍光発光分光法は、顔料から再構成された集光性タンパク質へのエネルギー移動の研究に使用できます。
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<div class="chapter_text" id="script_4">
膜タンパク質の再構成にゼウスのビデオを見てきただけ。再構成はさらに調査のため細胞模倣に重要な蛋白質を転送する方法です。このビデオ タンパク質溶解、溶解のプロトコル、および生化学のいくつかのアプリケーションの原則の説明。見てくれてありがとう!
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Reconstitution is the process of returning an isolated biomolecule to its original form or function. This is particularly useful for studying membrane ...

再構成とは、単離された生体分子を元の形や機能に戻すプロセスです。このアプローチは、多くの重要な細胞プロセスを可能にし、隣接する脂質の挙動に影響を与える膜タンパク質の研究によく使用されます。しかし、細胞環境の複雑さにより、膜タンパク質の機能をin situ.で研究することは困難です。タンパク質の抽出や精製は可能ですが、メンブレンがなければ実際の機能を評価することはできません。したがって、単離された膜タンパク質は、リポソームなどの人工脂質膜への組み込みによって「再構成」されます。このビデオでは、膜タンパク質の再構成の原理、一般的な再構成手順、および生化学におけるいくつかのアプリケーションを紹介します。細胞膜は、主にリン脂質と膜タンパク質で構成されています。リン脂質は二重層を形成し、親水性リン酸ヘッドは細胞の内部および外部の水性と相互作用し、疎水性脂肪酸テールは二重層内で互いに相互作用します。一部の膜タンパク質は、静電相互作用または非共有結合相互作用によってのみ膜と相互作用します。「内在性タンパク質」と呼ばれる他のものは、脂質二重層に埋め込まれています。二重層と同様に、内在性タンパク質は親水性末端と疎水性中心を持ち、疎水性相互作用によって所定の位置に保持されます。膜全体に広がる内在性タンパク質は、「膜貫通タンパク質」として知られています。これらのタンパク質と膜との間の相互作用は非常に強いため、細胞を溶解しても細胞を分離することはできません。たんぱく質を抽出するために、界面活性剤と呼ばれる特殊な界面活性剤が使われます。リン脂質と同様に、界面活性剤は親水性のヘッドと親油性のテールを持ち、膜に自由に入ることができます。メンブレン内では、界面活性剤の親油性テールが疎水性タンパク質のコアと相互作用します。これにより、タンパク質は親水性洗剤ヘッドの殻で囲まれ、タンパク質と脂質の相互作用が破壊されます。タンパク質-界面活性剤複合体は、膜から容易に分離できるようになりました。この界面活性剤は、複合体を水溶液に溶解させ、人工膜で再構成する準備を整えます。タンパク質は、人工小胞であるリポソームの膜で再構成されることがよくあります。リポソームを調製するために、乾燥した脂質を水和して攪拌し、小胞形成を誘導します。界面活性剤を添加すると、リポソーム膜に取り込まれます。タンパク質を再構成するために、可溶化したタンパク質とリポソームを結合させ、透析または化学吸着によって界面活性剤を溶液から除去します。タンパク質とリポソームは急速に集合してプロテオリポソームを形成するため、親水性基のみが露出します。その後、タンパク質は細胞膜内でと同様に機能し、単離して調査することができます。タンパク質の再構成の基本を説明したので、リポソームで膜タンパク質を再構成するためのプロトコルを見ていきましょう。膜タンパク質の単離を開始するために、細胞を溶解します。壊れていない細胞は遠心分離で除去されます。上清を高速で遠心分離して、メンブレンをペレット化します。ペレットを再懸濁し、界面活性剤を添加してタンパク質を抽出します。残りの細胞破片は、追加の遠心分離によって除去されます。タンパク質は、カラムクロマトグラフィーで上清から精製され、その後、必要に応じてさらに濃縮または精製されます。リポソームの調製を開始するには、有機溶媒中のリン脂質の懸濁液を窒素またはアルゴン下で乾燥させます。リン脂質を水和緩衝液で水和し、混合物を超音波処理してリポソームの作製を終了します。界面活性剤を添加してリポソームを可溶化し、リポソームをタンパク質と結合させます。その後、界面活性剤はポリスチレンビーズへの吸着、透析、または界面活性剤結合カラムによって除去されます。得られたプロテオリポソームは、精製してその後の実験で使用する準備ができています。膜タンパク質再構成手順の基本を理解したところで、生化学におけるタンパク質再構成のいくつかの応用例を見てみましょう。膜輸送タンパク質を再構成して、その輸送メカニズムをより明確に理解しました。再構成後の機能は、ヨウ化物イオンの流出により確認されました。次に、輸送活性を種々の低分子イオンチャネル阻害剤および増強剤の存在下で研究した。このようにして、これらの低分子と輸送タンパク質との直接的な相互作用を研究することができました。植物のクロロフィルおよびカロテノイド結合膜タンパク質は、光を収集し、電荷分離を促進し、光による損傷を軽減します。これらの光収集タンパク質を再構成することにより、それらのフォールディングダイナミクスと顔料との相互作用を研究することができます。この技術で再構成された光収集タンパク質は、天然タンパク質と非常によく似た光学特性を持っていました。その後、蛍光発光分光法を使用して、色素から再構成された光捕集タンパク質へのエネルギー移動を研究することができます。JoVEの膜タンパク質の再構成に関するビデオをご覧になりました。再構成は、重要なタンパク質を細胞模倣体に移し、さらなる研究を行う方法です。このビデオでは、タンパク質再構成の原理、再構成プロトコル、および生化学におけるいくつかの応用について説明しました。ご覧いただきありがとうございます!

Education

JoVE Science Education

Chemistry

化学

Biochemistry

生化学

membrane proteins in liposome models

Membrane proteins can be moved into liposome models so their function can be studied outside a cell. Reconstitution means restoring an isolated biomolecule to a working form. For membrane proteins, that usually means placing a purified protein into an artificial lipid membrane.

Cell membranes are made mainly of phospholipids and membrane proteins. The phospholipids form a bilayer with hydrophilic phosphate heads facing water and hydrophobic fatty acid tails facing inward. Some membrane proteins attach by noncovalent or electrostatic interactions, while integral proteins are embedded in the bilayer. Transmembrane proteins are integral proteins that span the full membrane, and their strong interactions with the membrane are not broken just by lysing cells.

Detergent is used to extract these proteins. Detergents have hydrophilic heads and lipophilic tails, so they can enter the membrane. Their tails interact with the hydrophobic protein core and surround it with detergent heads, which breaks protein-lipid interactions. The protein-detergent complex becomes soluble in water and is ready for reconstitution.

Liposomes are artificial vesicles often used for this step. They are made by hydrating dried lipids and agitating them to form vesicles. When detergent is added, it becomes part of the liposome membrane. The purified protein and liposomes are then mixed, and the detergent is removed by dialysis or chemical adsorption. As the detergent leaves, the protein and lipids assemble into proteoliposomes, with hydrophilic groups exposed to water. The reconstituted proteins can then work in a membrane-like setting and be studied in isolation.

A general liposome protocol starts with cell lysis. Unbroken cells are removed by centrifugation, and the membranes are pelleted at higher speed. The pellet is resuspended, detergent is added to extract the proteins, and more centrifugation removes leftover debris. The protein is then purified by column chromatography and concentrated if needed.

Liposome preparation follows a separate path. Phospholipids in organic solvent are dried under nitrogen or argon, then hydrated with buffer. Sonication finishes the liposome formation. After detergent is added to solubilize the liposomes, the proteins are combined with them. The detergent is removed with polystyrene beads, dialysis, or a detergent-binding column, leaving proteoliposomes that can be purified and used in later experiments.

Reconstituted membrane proteins have several uses in biochemistry. One transport protein was reconstituted to better understand how it moves molecules. Its activity was checked by the efflux of iodide ions. Researchers also tested small-molecule ion channel inhibitors and potentiators to study how they interact with the transport protein directly.

Plant light-harvesting proteins are another example. These chlorophyll- and carotenoid-binding membrane proteins help harvest light, support charge separation, and reduce light damage. After reconstitution, scientists can study folding dynamics and pigment interactions. The reconstituted proteins showed optical properties very similar to native proteins, and fluorescence emission spectroscopy can be used to follow energy transfer from pigments to the proteins.

Membrane Proteins in Liposome Models

dialysis: diffusion based separation

Dialysis for Buffer Exchange in Biochemistry

Dialysis is a common biochemistry technique for buffer exchange and desalting. It separates molecules by diffusion through a semipermeable membrane, which lets small molecules pass while holding larger biomolecules inside the sample. The membrane is the key part of the setup. Its pores create a molecular weight cutoff, so a membrane such as a 10 kDa membrane usually keeps molecules larger than 10 kilodaltons inside. This cutoff is not exact, because membranes have a range of pore sizes.

enzyme assays and kinetics

Measuring Enzyme Reaction Rates

Enzyme reaction rates can be measured with assays that track how substrate or product levels change over time. Enzymes are proteins, or sometimes RNAs, that speed up chemical reactions by lowering the activation energy needed to start them. They act on a specific substrate and help form a product that supports life processes. Enzymatic reactions are often described in three steps. First, the substrate binds to the enzyme active site and forms an enzyme-substrate complex. That complex can fall...

maldi-tof mass spectrometry

How MALDI-TOF Reads Biomolecules

MALDI-TOF mass spectrometry reads biomolecules by using a laser, a matrix, and a time-of-flight analyzer. MALDI, or matrix-assisted laser desorption ionization, helps fragile molecules keep their structure while they are moved into the mass analyzer. The analyzer then separates compounds based on size and charge. In MALDI, the sample is mixed into a matrix, usually an organic compound with aromatic and conjugated double bonds. A laser pulse strikes the spot, and the matrix absorbs most of the...

tandem mass spectrometry

Tandem Mass Spectrometry for Biomolecule Analysis

Tandem mass spectrometry is used to isolate a biomolecule and break it into smaller pieces so its makeup can be studied. Because biomolecules often have large, complex structures, it can be hard to identify their molecular composition and sequence from a single measurement. By linking mass spectrometers in series, the technique first selects one ion and then analyzes the fragments it produces. The process starts with an ion source that converts the sample into ions. A mass analyzer then...

protein crystallization

Protein Crystals for Structure Analysis

Protein crystals help scientists study protein structure and function. A crystal is a solid lattice made from purified protein molecules. These crystals are useful in structural biology because they reveal details that methods like mass spectrometry and SDS-PAGE cannot show on their own. Protein crystallization is paired with recombinant protein expression and x-ray diffraction to support this work. The process starts with a large amount of very pure protein. Researchers often make that...

chromatography-based biomolecule purification methods

chromatography-based-biomolecule-purification-methods

Protein Purification with SEC and IMAC

Protein purification with size-exclusion chromatography and affinity chromatography helps isolate biomolecules from complex mixtures. These methods are common in biochemistry because purified samples are needed before a biomolecule’s properties and activity can be studied. The video focuses on the principles behind size-exclusion chromatography, affinity chromatography, and immobilized metal affinity chromatography, or IMAC. Size-exclusion chromatography, or SEC, separates molecules by size. A...

two-dimensional gel electrophoresis

Protein Mapping with 2D Gel Electrophoresis

Protein mapping with 2D gel electrophoresis separates complex protein mixtures across two steps. The method combines isoelectric focusing, or IEF, with sodium dodecyl sulfate polyacrylamide gel electrophoresis, or SDS-PAGE. Together, these methods can resolve thousands of biomolecules from a single sample by their isoelectric point and molecular weight. The first dimension is IEF. Each protein has an isoelectric point, or pI, which is the pH where its net charge is zero. Proteins are loaded...

metabolic labeling

Tracking Cell Chemistry with Metabolic Labels

Metabolic labeling tracks cell chemistry by using chemical analogs that cells take up and build into biomolecules. These labels help scientists follow biochemical changes and modifications inside cells. The labeled products can then be studied with tools such as SDS-PAGE and NMR to learn more about metabolic pathways. Several labeling strategies are shown here. Isotopic labeling uses analogs that match the natural molecule but contain uncommon isotopes, such as carbon-13 and nitrogen-15 in an...

electrophoretic mobility shift assay (emsa)

electrophoretic-mobility-shift-assay-emsa

Detecting Protein-DNA Binding by EMSA

Electrophoretic mobility shift assay, or EMSA, is a biochemical method used to detect binding between proteins and nucleic acids. It is also called a gel shift assay. The test compares how a labeled nucleic acid moves through a gel before and after it binds a protein. EMSA is used to see whether a specific protein binds to a specific nucleic acid. First, the nucleic acid is labeled to make a probe. The transcript describes radioactive phosphorus-32 as a common label. The probe is then mixed...

photometric protein determination

Measuring Protein Concentration with Absorbance

Measuring protein concentration with absorbance is a key step in many biochemical assays. Photometric methods use the fact that samples with more light-absorbing material transmit less light. Because concentration and absorption are directly related, this makes it possible to measure an unknown sample. The core idea comes from the Beer-Lambert Law. This law states that the concentration of a light-absorbing species is proportional to its absorbance. The video also introduces the Bradford assay...

density gradient ultracentrifugation

Sucrose Gradient Separation in an Ultracentrifuge

Sucrose gradient separation in an ultracentrifuge is a lab method for isolating cell parts and biomolecules. It uses differences in density to make particles sink or rise in a liquid. A high-speed ultracentrifuge speeds up this process so components can be separated without destroying them. The basic idea starts with a suspension, which is particles mixed in a liquid solvent. Particles that are denser than the solvent sediment, while less dense particles float. A rotor inside the...

co-immunoprecipitation and pull-down assays

co-immunoprecipitation-and-pull-down-assays

Protein Interaction Capture Methods in Cells

Co-immunoprecipitation and pull-down assays are laboratory methods used to capture stable protein-protein interactions. Protein-protein interactions help control many biological functions, but many of them have not yet been identified. These assays are related to immunoprecipitation, which isolates a target protein from a mixed sample using an antibody. In co-immunoprecipitation, or CoIP, an antibody binds the target protein, and that protein is already attached to another protein that the...

reconstitution of membrane proteins

Membrane proteins can be moved into liposome models so their function can be studied outside a cell. Reconstitution means restoring an isolated biomolecule to a working form. For membrane proteins, that usually means placing a purified protein into an artificial lipid membrane. Cell membranes are made mainly of phospholipids and membrane proteins. The phospholipids form a bilayer with hydrophilic phosphate heads facing water and hydrophobic fatty acid tails facing inward. Some membrane...

f&#246;rster resonance energy transfer (fret)

FRET as a Molecular Ruler in Cells

Föster resonance energy transfer, or FRET, is a way to study close-range biochemical interactions using light-emitting molecules. A donor fluorophore can pass energy to an acceptor fluorophore when their emission and absorption spectra overlap. This transfer happens only when the pair is very close together, usually within 10 nm. Because FRET depends on distance, it is often called a molecular or spectroscopic ruler. The strength of the signal is measured as FRET efficiency, which describes...

surface plasmon resonance (spr)

SPR Biosensors for Tracking Binding Kinetics

Surface plasmon resonance, or SPR, is a way to track biomolecular binding on a label-free biosensor. It is used to measure molecular affinity, kinetics, specificity, and concentration. The method works with a thin metal layer on a prism, where changes in reflected light reveal interactions in real time. SPR sensors use a thin layer of a noble metal on the face of a prism. Light is reflected from the prism-metal interface into a photodetector. At one specific angle, called the surface plasmon...

biochemistry

このコレクションでは、親和性クロマトグラフィーなどの一般的に使用される精製方法や、MALDI-TOFなどの分析方法について紹介します。さらに、共同免疫沈降法や代謝標識法など、生体分子の相互作用や機能を評価する方法も紹介します。

See how membrane proteins are extracted with detergent and reinserted into liposomes so students can study transport and light-harvesting function.

Membrane Proteins in Liposome Models | JoVE K12

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

HS-LS1-5.

HS-LS1-6.

Overview

Principles of Membrane Protein Reconstitution

Protocol for Reconstitution of Membrane Proteins in Liposomes

Applications

Summary

Characteristics of Life

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

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

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 ...

DNA Methylation Analysis

Methylation at CpG dinucleotides is a chemical modification of DNA hypothesized to play important roles in regulating gene expression. In particular, the ...

Expression Profiling with Microarrays

Microarrays are important tools for profiling gene expression, and are based on complementary binding between probes that are attached to glass chips and ...

Density Gradient Ultracentrifugation

Density gradient ultracentrifugation is a common technique used to isolate and purify biomolecules and cell structures. This technique exploits the fact ...

F&#246;rster Resonance Energy Transfer (FRET)

F&#246;rster resonance energy transfer (FRET) is a phenomenon used to investigate close-range biochemical interactions. In FRET, a donor photoluminescent ...

detecting-environmental-microorganisms-with-polymerase-chain-reaction

Detecting Environmental Microorganisms with the Polymerase Chain Reaction and Gel Electrophoresis

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Bradley Schmitz
Polymerase chain reaction (PCR) is ...

Gel Purification

Gel purification is used to recover DNA fragments after electrophoretic separation. DNA recovery from an agarose gel includes three basic steps: binding, ...

Detecting Reactive Oxygen Species

Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are ...

Gene Silencing with Morpholinos

Morpholino-mediated gene silencing is a common technique used to study roles of specific genes during development. Morpholinos inhibit gene expression by ...

development-and-reproduction-of-the-laboratory-mouse

Development and Reproduction of the Laboratory Mouse

Successful breeding of the laboratory mouse (Mus musculus) is critical to the establishment and maintenance of a productive animal colony. Additionally, ...

Genetic Crosses

To dissect genetic processes or create organisms with novel suites of traits, scientists can perform genetic crosses, or the purposeful mating of two ...

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.

Membrane Proteins in Liposome Models

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