Ussing Chamber Function

 

The Ussing chamber provides a enclosure to measure the transport of ions, nutrients, and drugs across various epithelial tissues. It consists of two halves separated by the epithelia An Ussing chamber can isolate the apical side from the basolateral side. read more

 

Types of Ussing Chambers

The three main types of Ussing chamber systems are

1. The Classic chamber system (as designed by Ussing).
2. Self-contained chamber system (the full apparatus within a single block)
3. Multi-channel chamber system (2 to 24 independent chambers combined)

read more.

 

Ussing Chamber Accessories

 

Cell Culture Holders

Tissue and Cell Culture holders, we call “sliders”, built to accommodate popular culture inserts from manufacturers such as Snapwell, Transwell, Corning-CoStar, Nunc, Millipore and more.

 

History of Ussing Chambers

 

Hans Henriksen Ussing (12/30/1911 – 12/20/2000) was a Danish scientist, best known for having invented the Ussing chamber.

Hans Ussing InventorIn the early 1950s Ussing was the first to describe the mechanism by which ions are actively transported across frog skin.

He studied biology and geography at the University of Copenhagen. In 1943 he received his master’s degree, graduating with honors.

In 1970 he was awarded the Amory Prize of the American Academy of Arts and Sciences.

As a zoologist, Hans H. Ussing began his scientific career by studying the marine plankton fauna in East Greenland. This brought him in contact with August Krogh at the time George de Hevesy, Niels Bohr and Krogh planned the application of artificial radioactive isotopes for studying the dynamic state of the living organism. Following his studies of protein turnover of body tissues with deuterium-labeled amino acids, Ussing initiated a new era of studies of transport across epithelial membranes. Theoretical difficulties in the interpretation of tracer fluxes resulted in novel concepts such as exchange diffusion, unidirectional fluxes, flux-ratio equation, and solvent drag. Combining methods of biophysics with radioactive isotope technology, Ussing introduced and defined the phrases ‘short-circuit current’, ‘active transport pathway’ and ‘shunt pathway’, and with frog skin as experimental model, he unambiguously proved active transport of sodium ions. Conceived in his electric circuit analogue of frog skin, Ussing associated transepithelial ion fluxes with the hitherto puzzling ‘bioelectric potentials’. The two-membrane hypothesis of frog skin initiated the study of epithelial transport at the cellular level and raised new questions about cellular mechanisms of actions of hormones and drugs. His theoretical treatment of osmotic water fluxes versus fluxes of deuterium labeled water resulted in the discovery of epithelial water channels.
His discovery of paracellular transport in frog skin bridged studies of high and low resistance epithelia and generalized the description of epithelial transport. He devoted the last decade of his scientific life to solute-coupled water transport. He introduced the sodium recirculation theory of isotonic transport, and in an experimental study, he obtained the evidence for recirculation of sodium ions in toad small intestine. In penetrating analyses of essential aspects of epithelial membrane transport, Ussing provided insights of general applicability and powerful analytical methods for the study of intestine, kidney, respiratory epithelia, and exocrine glands—of equal importance to biology and medicine.

An Ussing chamber is used to study solute transport across a confluent layer of cells. This layer is typically a monolayer of epithelial cells which form a barrier between the external and internal environments of the body such as those that line the airways, intestinal tract and bladder, but could also be a multilayered structure such as skin or 3D cell culture or a confluent layer of endothelial cells such as blood brain barrier in culture or corneal endothelium. Solute transport may be determined by measuring the flux of the solute or sometimes, in the case of charged solutes such as ions, by measuring the current across the tissue. These electrical parameters, together with tissue resistance, serve to assess ion transport and tissue integrity.

In order to accomplish these measurements Ussing systems have been designed to have three main components; namely, Ussing chamber, voltage/current clamp and data acquisition system.

1) The Ussing chamber is simply a device that enables one to place the tissue between two solution-filled compartments. The chamber may be fitted with electrodes for measuring voltage and passing current across the tissue.

2) The voltage current clamp is used to control either the voltage or the current across the epithelium and thereby determine bioelectrics such as transepithelial voltage, short-circuit current and resistance or conductance.

3) Results of the electrical measurements may be recorded using something as simple as a chart recorder or newer electronic versions of a chart recorder. Alternatively, it can be collected by an intelligent data acquisition system that acts as a chart recorder but also measures and plots tissue resistance or conductance in real time such as Acquire & Analyze. Full featured Ussing systems that are comprised of EasyMount Ussing Chamber system, multi-channel voltage current clamp instruments and Acquire & Analyze data acquisition package along with accessories to establish a nearly complete, working system.

 

More types of Ussing Chambers

 

 Cell & Tissue Systems:

Ussing Chamber system design that includes individual Ussing chambers, a heating block for temperature control, needle valves for adjustment of gas flow used for oxygenation and gas lift stirring, Ag/AgCl reference electrodes for measuring transepithelial voltage and passing current and leads for connecting the electrodes to the voltage/current clamp. The system has been designed for both ease of use and easy cleanup. Tissues and cell culture inserts are first placed into a special holder that is then simply slid into position in the chamber. Unlike other systems, the chambers do not have to be removed from the heat block nor do the electrodes have to be disturbed, etc. Pricing for the systems depends on the number and type of chambers selected as given below. Please consult factory for a complete description and to discuss the chamber design most suited for use with your tissue samples and experiments.

 

Low Volume Systems

Low volume Ussing chamber system for used to study transport in tissues where the net quantity transported is low or the assay for the transported solute requires higher concentrations. This system, like the system for Snapwell culture inserts above, permits a variety of tissue sizes to be mounted in a low volume chamber.

 

Rat Systems

The basic Easy Mount system described above, P2250 chambers specifically designed for mounting intestinal tissues using an oblong aperture 5 x 22 mm to yield 1.0 cm2 tissue area. Tissues are mounted by pressing the tissue over short, curved pins lining a matching aperture on a slider (P/N P2252). Other custom sliders can be made. Please consult manufacturer. Usable half chamber volume range is 2.0 – 8.0 ml.

 

Frequently Asked Questions

 

Frequently asked questions about Ussing Chambers.

 

What is an Ussing Chamber?

An Ussing chamber is a scientific tool used to measure the short-circuit current as an indicator of net ion transport taking place across an epithelium. Ussing chambers are increasingly being used to measure ion transport in both native tissue, like gut mucosa and monolayer of cells grown on permeable supports.

 

What are Ussing chamber systems?

Ussing chambers are scientific instruments used to study the transport of ions and water across biological membranes, such as those found in the walls of cells and tissues. The Ussing chamber system consists of a pair of glass or plastic chambers that are separated by a thin layer of tissue. The chambers are typically perfused with different solutions, and a voltage is applied across the tissue to stimulate the movement of ions through the membrane. Researchers use Ussing chambers to study the properties of biological membranes and the mechanisms by which ions and water are transported across them. This can help to better understand the physiological functions of cells and tissues, as well as the effects of various substances on these processes.

 

How does and Using Chamber Work?

An Ussing chamber consists of two halves that are clamped together having the epithelia (sheet of mucosa or monolayer of epithelial cells grown on permeable supports). Note: Epithelia are polar in nature, i.e., they have an apical or mucosal side and a basolateral or serosal side. Thus in an Ussing chamber it is possible to isolate the apical side from the basolateral side. The two half chambers are filled with equal amount of symmetrical Ringer solution in order to remove any chemical, mechanical and electrical driving forces. In any epithelium there is ion transport taking place across it be it from apical side to basolateral side or vice-versa. This ion transport produces a potential difference (voltage difference) across the epithelium. The voltage difference generated is measured using two voltage electrodes that are placed nearer to the tissue/epithelium. And this voltage is cancelled out by injecting the current using another two current electrodes that are placed away from the epithelium. This amount of current injected is called Short-circuit current (Isc) and is the exact measure of net ion transport taking place across the epithlium.

 

Ussing chambers are scientific instruments

Ussing chambers are scientific instruments that are used to study the transport of ions and water across biological membranes. They were first developed in the 1940s by Danish scientist Hans Ussing, and have since become an important tool in a wide range of scientific disciplines, including physiology, pharmacology, and toxicology.

The Ussing chamber system consists of two glass or plastic chambers that are separated by a thin layer of tissue. The tissue can be derived from a variety of sources, including small intestine, bladder, or skin. The chambers are typically perfused with different solutions, and a voltage is applied across the tissue to stimulate the movement of ions through the membrane.

Researchers use Ussing chambers to study the properties of biological membranes and the mechanisms by which ions and water are transported across them. This can help to better understand the physiological functions of cells and tissues, as well as the effects of various substances on these processes. For example, Ussing chambers have been used to study the effects of drugs on the absorption of ions and water in the intestines, and to understand the mechanisms underlying the absorption of nutrients and the secretion of hormones in the pancreas.

Ussing chambers have several advantages over other methods for studying ion transport. They allow researchers to study the transport of ions and water across a single, well-defined membrane, rather than relying on measurements of bulk fluid movement or whole-organ function. They also allow researchers to study the transport of ions and water under controlled conditions, such as different pH levels or different concentrations of ions.

Overall, Ussing chambers are an important tool for understanding the transport of ions and water across biological membranes, and have helped to advance our understanding of the physiological functions of cells and tissues.