Applications

See How Our Products Are Used In a Wide Variety Of Applications.

  1. Two Electrode Voltage Clamp of Oocytes

    Two Electrode Voltage Clamp of Oocytes

    The voltage clamp technique is a method that allows ion flow across the cell membrane to be measured as an electric current as the transmembrane potential is held under constant experimental control with a feedback amplifier. Ion channels expressed in Xenopus oocytes can be studied using the two-microelectrode voltage clamp. The membrane of the oocyte is penetrated by two microelectrodes, one for voltage sensing and one for current injection. The membrane potential as measured by the voltage-sensing electrode and a high input impedance amplifier is compared with a command voltage, and the difference is brought to zero by a high gain feedback amplifier. The injected current is monitored via a current-to voltage converter to provide a measure of the total membrane current.

    Equipment:

    • npi TEC-05X-CC or npi TEC-10CX
    • KS 9211 table
    • ALA PPH-0P-BNC holders
    • ALA VC38 with ALA PR-10 and ALA VWK
    • npi ScreenTool Package
    • MCS Roboocyte
    • MCS HiClamp
  2. Macropatch Recording

    Macropatch Recording

    The technique for macropatching is similar to tight seal single-channel recording. The electrodes are pulled to larger tip diameters than would be used for single-channel recording; however, with single-channel recording, following initial contact with the membrane, suctions is applied to form an electrically and mechanically tight seal in gigohm range. Recordings can be obtained in the cell-attached configuration or from inside-out or outside-out membrane patches.

    The objective, for many laboratories using this technique, is to record from specific areas of the membrane relative to known specializations, for example, the distribution of the ion channels in the pre- or postsynaptic membrane, dendritic vs somatic membranes. Macropatch electrodes have resistances in the range 0.5-3MOhms and are in the order of 2-8um diam. Our range of HEKA and NPI patch clamp amplifiers are particularly suited for such recordings.

    Equipment:

    • HEKA EPC-10
    • KS 9100 series table
    • ALA VC3 with  ALA PR-10 and ALA MLF or ALA OctaFlow
    • ALA MS Chambers
    • HEKA PatchMaster
    • ALA HSSE-2/3
  3. Single-Channel Recording

    Single-Channel Recording

    Single-channel recording is achieved by pressing a fire-polished glass pipette, which has been filled with a suitable electrolyte solution, against the surface of a cell and applying light suction. Under such conditions, the glass pipette and the cell membrane will be less than 1 nm apart. The tighter the seal will have two advantages, 1) better electrical isolation of the membrane patch and 2) a high seal resistance reduces the current noise of the recording, permitting good time resolution of single channel currents, currents whose amplitude is in the order of 1 pA. Classically, three different configurations of the patched membrane can be used for single-channel recording: cell-attached, outside-out and inside-out patches. Cell-attached configuration contacts the cell membrane forming a gigaohm seal. Long-term stable recordings with low background noise can be performed in this configuration with minimal disruption to the intracellular milieu. For the outside-out configuration, the external surface of the patch is exposed to the external recording media. Offering the opportunity to repetitively expose the channels to different drugs and at various concentrations. In the inside-out patch configuration, it is the internal face of the membrane that is exposed to the external solution. This provides access to intracellular receptor binding sites and also enables studies of intracellular signaling pathways.

    It is now possible to record single-channel current activity from many cell types, that is, from mammalian species, insects, invertebrates and also plants. The recording of single-channel currents enables detailed kinetic analyses of native and recombinant ion channels, including those that have been subject to natural or intended mutations to their structure.

    Equipment:

    • HEKA EPC-10
    • KS 9100 series table
    • ALA VC3-8 with ALA PR-10 and ALA MLF or ALA OctaFlow
    • ALA MS Chambers
    • HEKA PatchMaster
    • Bruxton TAC
  4. Whole-Cell Recording

    Whole-Cell Recording

    Whole cell recording is the most commonly used configuration of the patch clamp technique. It is achieved by rupturing the patch of membrane isolated by the patch pipette bringing the cell interior into contact with the pipette interior. Using the whole cell patch clamp design of experiment one can then record the electrical activity of the entire cell via several modes. Voltage clamp, where the potential difference across the cell membrane is controlled and current measured, or current clamp, controlling the current and measuring the voltage across the membrane are the two main modes of whole cell recording. These recording configurations are very powerful techniques in the study of ion channel activity, aspects of neuronal behaviour and synaptic transmission. Our range of HEKA and NPI patch clamp amplifiers are perfect for carrying out whole cell patch clamp recordings.

    One major problem in whole recording is series resistance. Employing the ‘Discontinuous single electrode voltage clamp’ (dSEVC) technique is a very useful procedure to overcome the series resistance. The dSEVC separates the current injection from potential measurement in time, by rapid switching between a current injection mode and potential measuring mode. This ensures that no current passes through the resistor created at the pipette/cell interface during potential recording and completely eliminates series resistance artifacts. Provided the switching frequency between the current injection- and voltage measuring-mode is high enough, the plasma membrane can be clamped to a steady membrane potential. Our NPI SEC range of amplifiers are designed specifically for dSEVC being the fastest and most accurate single-electrode current – and voltage – clamp systems available.

    Equipment:

    • HEKA EPC-10
    • KS 9100 series table
    • ALA VC3 with ALA PR-10 and ALA MLF or ALA OctaFlow
    • ALA MS Chambers
    • HEKA PatchMaster
    • ALA HSSE-2/3
  5. Cardiac Rhythmicity

    Cardiac Rhythmicity

    The spontaneous depolarization and repolarization events that occurs in a repetitive and stable manner within the cardiac muscle is often abnormal or lost in cases of cardiac dysfunction or cardiac failure. The underlaying mechanisms of this rhythmicity are based on the myriad of voltage dependent ion channels found in cardiac myocytes. These ion channels can then be studied at the single channel, single cell or tissue level using various techniques and equipment supplied by ALA Scientific Instruments.

    The use of the patch clamp technique is very powerful at the single channel and single cell (whole cell) level. Such amplifiers as the manufactured by HEKA and NPI are ideal. In addition, ALA Scientific Instruments range of perfusion systems make cardiac experiments very easy. At the tissue level, MCS multielectrode arrays are capable of recording from distinct regions of cardiac slices simultaneously.

    In Vitro Cell and Tissue Preparations

    Equipment:

    • MCS MEA60-BC system
    • ALA VC3-4
    • ALA VWK

    In Vivo Multielectrode Recording

    Equipment:

    • MCS ME-32-System
    • MCS FlexArray
  6. Systems Neuroscience

    Systems Neuroscience

    The function of neuronal circuits and systems can only be studied with preparations and experimental models where neurons are connected together to form neural networks. In vitro preparations such as acute brain slices and organotypic slices are ideal models from which to investigate neural circuits. Acute slice and organotypic preparations are used in conjuction with multielectrode arrays to record from many neurons, or populations of neurons, simultaneously. Experimenters can utilise these systems for diverse projects including, long term potentiation in hippocampal slices, micro electroretinograms from retinal explants or spontaneous rhythmic activity from cardiomyocyte cultures.

    Equipment:

    • MCS ME system
  7. Gap Channel Conductance

    Gap Channel Conductance

    Gap junctions are formed between the opposing membranes of neighbouring cells. Hemichannels (connexons)on each side dock to one another to form conductive channels between the two cells. The main role of gap junctions is in the electrical synaptic transmission of the nervous system allowing direct and rapid communication between neurons. The measurement of the electrophysiological properties of gap junctions is carried out using the dual whole cell voltage clamp technique. The dual voltage clamp method is the common method to assay the electrical properties of gap junctions, such as junctional conductance and transjunctional voltage dependence.

    Equipment:

    • Dual SEC-05 system w/ INST ITC-18, EPMS-7 modular system with SEC modules and INST ITC-18, or HEKA EPC-10/2
    • HEKA PatchMaster
    • Dual Scientific PatchStar system
    • KS 9100 series table
  8. Exocytosis

    Exocytosis

    Exocytosis is the process in which the contents of secretory vesicles are released by their fusion to the plasma membrane and plays a vital role in signaling of the nervous and endocrine system. Exocytosis can be detected by several physical and chemical means. By chemically oxidizing the released secretory products at a fixed electrode potential, carbon fiber amperometry provides excellent temporal and spatial resolution in detecting exocytosis. Among the most intensively studied products include, norepinephrine, epinephrine, dopamine, and serotonin. ALA can provide full systems suitable for recording this process. The VA-10 amplifier is a sensitive (picoampere range) current amplifier that is specifically designed for voltammetric and amperometric measurements with carbon-fiber microelectrodes in biological systems. It was designed at the Max-Planck-Institute for Experimental Medicine in Göttingen as an economically priced alternative to do-it-yourself systems and expensive commercial systems.

    It can be used for either DC amperometry using the built-in voltage source, or it can be operated with user-supplied external voltage waveforms (e.g. for cyclic voltammetry). The VA-10X is ideally suited for measurements from single cells plated onto glass cover slips and with carbon-fiber disk electrodes having diameters of 10 µM or less. Carbon fibre electrodes, CFE-1, are hand made at ALA Scientific Instruments and individually tested to ensure viability.

    Equipment:

    • Npi VA-10 Amplifier
    • Instrutech ITC-18 data acquisition card
    • HEKA PatchMaster
    • KS 9100 Series Table
  9. Ion Channel Pharmacology

    Ion Channel Pharmacology

    Ion channels are involved in many cellular processes, drugs acting on ion channels have long been used for the treatment of many diseases, especially those affecting electrically excitable tissues. Combined with advancements in high throughput screening of ion channels in drug discovery, elucidating ion channel pharmacology has grown into an enormous global task. Because of the high information content, voltage clamp is the best way to study ion-channel function which is superbly provided by the HEKA and NPI systems.

    Ion channel pharmacology is ultimately dependent upon the application of the particular drug in question. Such drug application is provided depending on your needs. Computer controlled local perfusion is provided by ALA Octaflow and VC systems. Submillisecond application of drugs can be achieved by the ALA HSSE-2 system. Your drug of choice can also be applied to the internal of cells during whole cell recording using the ALA 2PK+ system. A wide variety of manifolds, perfusion chambers and other accessories allows the ion channel pharmacologist to easily design a system to suit their requirements.

    Classical Compound Application

    Equipment:

    • HEKA EPC-10 or npi SEC-05 w/ INST ITC-18
    • HEKA PatchMaster
    • KS 9100 Series table
    • ALA OctaFlow
    • ALA Chamber
    • ALA VWK

    Pipette Internal Solution Exchange

    Equipment:

    • HEKA EPC-10 or npi SEC-05 w/ INST ITC-18
    • HEKA PatchMaster
    • KS 9100 Series table
    • ALA 2PK+
    • ALA Chamber
    • ALA VWK
  10. Brain/Spinal Cord Slice Recording

    Brain/Spinal Cord Slice Recording

     

    Techniques developed in 1989 by two groups (Edwards et al & Blanton et al) allowed direct patch clamping from neurons in acute slices of brain and spinal cord. This technical achievement overcame the problems of using neurons in culture which had been treated with enzymes and displayed altered gene expression and synaptic functions. The use of brain and spinal cord slices have since been extensively used to answer some fundamental questions in neurobiology such as the fundamental mechanism of inhibitory and excitatory neurotransmission as well as identifying single channel characteristics of ion channels found natively in the brain.

    Many ALA products are suited for brain slice electrophysiology. Constant perfusion is a key requirement for the viability of slices and the ALA VC3 system is ideal for controlling the change in bathing solutions during experiments. Extracellular field recordings are ideally carried out using NPI EXT-02F extracellular amplifier and ISO-Stim Isolated Stimulator combination.

    Whole cell recordings are routinely carried out in slices using HEKA EPC amplifiers or the NPI ELC or SEC amplifiers. Slices are also the most common preparation used in Multielectrode array experiments.

    Hippocampal Slice Recording Signals 

    Multi Electrode Arrays

    Equipment:

    • MCS MEA60 System
    • ALA VC3-4PG

    Extracellular Micropipettes

    Equipment:

    • Npi EPMS chassis
    • Npi EXT module
    • Npi Signal Conditioning Module
    • Npi Stimulator Module
    • ALA PPH-0P-BNC Holders
  11. Retinal Physiology

    Retinal Physiology

    Classical Extracellular Recording

    Equipment:

    • Npi EPMS Chassis
    • Npi EXT Module
    • Npi Signal Conditioning Module
    • Npi Stimulator Module
    • ALA PPH-0P-BNC Holders

    Multielectrode Array Recording

    Equipment:

    • MCS MEA60 system
  12. Invertebrate Preparations

    Invertebrate Preparations

    Equipment:

    • Npi EPMS Chassis
    • Npi EXT Module
    • Npi Signal Conditioning Module
    • Npi Stimulator Module
    • ALA PPH-0P-BNC Holders

We are constantly working on our Applications section to make it more comprehensive and accurate. We welcome your comments and suggestions. Please Click Here to submit your thoughts.