Laboratory centrifuges rotate objects on an axis which applies a strong outward force to separate substances within a suspension or immiscible liquid. Through centrifugal force, the denser substances are driven away from the axis, while the less dense substances are pulled to the center. When the spinning stops, the dense substances would naturally reside at the bottom of the container, while the less dense substances float to the top.

There are different types of centrifuges based on its use and rotor design. Laboratory centrifuges, as described above, are used for laboratory research and if mostly used to separate different substrates of various densities. This type is the most commonly used centrifuge because it can be used for a variety of purposes, even outside the laboratory setting.

Analytical ultracentrifuges are used specifically to for sedimentation analysis to determine the size of solutes, dispersion and sedimentation patterns. Haematocrit centrifuges are exclusively used in blood preparations to measure the percentage of the different blood cells. Gas chambers are used to separate gasses.

The rotor design of the centrifuge also fits its intended purpose. Fixed-angle centrifuges hold the sample containers at an angle. This is the most common rotor design for majority of centrifuges. Swinging head holds containers either horizontally or vertically, allowing all substances to spin within the same plane. This type is suited for slow rotating speeds to analyze large volume samples and is generally seen in Haematocrit centrifuges. Continuous tubular centrifuges do not use individual sample vessels and are mainly seen in ultracentrifuges or in models designed to separate DNA materials.

Laboratory circulators are used to control the temperature of fluids, especially those involving liquid baths. Laboratory circulators provides constant monitoring, maintenance and precise temperature setting, either heating or cooling the liquid depending on the parameters required.

Most models of laboratory circulators have three general parts. These are the liquid reservoir, the temperature control systems, and the heating and cooling system. More sophisticated models designed to work with large amounts of liquid generally do not have a liquid reservoir and are compatible with other liquid monitoring systems. Standard temperature range is –95 °C to 200 C° and have a pump capacity of at least 10 – 20 liters per minute. >/p>

More sophisticated and more expensive models have a higher temperature range, have a larger pump capacity and have a digital display. While circulators that have these specifications are impressive, their expensive cost are generally not worth it if not used within highly specific and detailed research. For general purposes, a model that have average specification is more suitable, less expensive and practical, with the same level of effectiveness compared with more expensive models, for general applications.

Colony counters are used in biological studies to determine the number of bacteria in a colony on a petri dish. Rudimentary counters are often grid attachments to microscope oculars that help scientists manually count the number of identified bacteria within a grid, and then use a formula to make a good estimate on the correct number of bacteria. Modern day colony counters replicate the same formulae electronically, resulting into faster and more accurate estimates.

While, majority of automatic colony counters use the same principle, different models have different specifications and sensitivity depending on the need of the research. For instance, while, most automatic counters have LCD displays, some have larger and clearer screen size to view the colony itself, while cheaper models only have a small LCD display that shows the bacterial count. Smaller and low-cost models also still use a magnifying lens for manual viewing of the bacterial colony, while more advanced models have high definition cameras, shadow filters and LED lightning for better viewing. In most cases, these additional features have no practical use outside of laboratories that perform high level research making the less expensive models more desirable for schools, education and basic research.

Laboratory coolers can either cool liquid baths, solutions, test samples and other substances in the lab. In terms of function, laboratory coolers are similar to refrigerator freezers. The main difference is that laboratory coolers are faster at reaching freezing temperature and have a wider temperature range depending on the model’s wattage. The higher the wattage, the higher the cooling capacity of the cooler. Coolers can either use liquid or gas as their cooling agent depending on the model.

Laboratory coolers come in all shapes and sizes depending on the samples they can hold. Benchtop coolers are mostly used to cool or freeze smaller containers such as those containing enzymes, cells, regents and solutions. Most benchtop coolers have a ‘quick freeze’ feature that rapidly freezes samples within a few minutes. Larger models are often more versatile since benchtop models are often limited by their size. Larger coolers are used to cool down or freeze large liquid baths, larger batches of laboratory samples, and even conserve water in laboratories since many larger cooler models can reuse chilled liquid to maintain cold temperature.

Dry block heaters are used to heat laboratory samples, specifically on enzyme digestion, catabolism, incubation, DNA amplification, activation of bacterial cultures, nucleic acid studies and experiments concerning different melting/boiling point of test samples. Dry block heaters are generally preferred because they can quickly reach high levels of temperature, depending on their wattage.

As their name implies dry block heaters does not use liquids or vapors to heat their surface, but rather use electrical power for their heaters. Most dry block heaters use microprocessor technology to manage the high electrical power needed for heating. Using this technology not only results into faster heating times, but also more accurate temperature readings as well.

Hot plates are used to quickly warm laboratory samples. The most common use of hotplates is to heat liquids above boiling point that are stored in glasswares such as flasks and beakers. Because of this, many hot plate models have built-in magnetic stirrers for solutions and chemicals that needs continuous stirring during heating.

Hot plates are generally considered to be low-cost laboratory equipment compared to its utility, considering that hot plates can serve multiple functions outside of heating solutions. Hot plates also does a better job of distributing heat over an area, making it easier for the user to regulate and monitor the temperature of the heated solution. Furthermore, compared to other heating options, hot plates are the most ideal since they can generate moderately high levels of heat (up to 400 degrees Celsius) quickly and present lesser health risks compared to other heating options such burners and liquid baths that can potentially cause fire, burns or injury.

There are different types of hot plates based on their top coating. The most widely used are aluminum hot plates because aluminum provides a rapid heating surface that distributes easily and quickly throughout its area. The only disadvantage is that the aluminum top is vulnerable to corrosive chemicals and can easily be damaged. The other types are ceramic and enamel. Both types are similar since they are both durable compared with aluminum. However, ceramic and enamel surfaces are not as good compared to aluminum in distributing heat.

Immersion heater circulators are a specific type of circulators that aim to maintain the temperature and circulate warm liquid. Immersion heater circulators are useful in a variety of settings outside of laboratory research that includes hazardous waste management and biomedical studies. This device has also found its niche in the kitchen as a viable cooking technique that is based on cooking meat in lower temperatures.

Like circulators, immersion heater circulators are composed of a mechanical pump that circulates the liquid, temperature control systems and a temperature probe for accurate measurements. Most laboratory heater circulators can maintain liquids at boiling point and can easily do so within a short amount of time.

Incubators are primarily used in biological studies as a secure way to grow and maintain microbiological and tissue cell tissues. An incubator can easily maintain the temperature, pressure, humidity needed for microbial life to flourish. Additionally, incubators make it easier to control concentration between oxygen and carbon dioxide, easily simulating ideal atmospheric conditions needed for microbial life to grow.

Different models of incubators are used depending on what type of microbial life are needed to cultivate. Generally, incubators have a temperature range between 20 to 65 °C with some models reaching higher temperatures. More complex models would also have more advanced options for controlling the humidity and pH level inside the incubator. The goal is to mimic natural conditions as much as possible to ensure that the microbial like will multiply as needed. Additional features that allows controlling carbon dioxide levels also makes it possible to grow microbes that do not need oxygen to multiply in the laboratory.

Microscopes are instruments used to observe small objects that cannot be seen by the naked eye. Often, these objects are microscopic organic life forms such as small animals or plants or cellular components such plant and animal cells and issues. These objects can be viewed either through prepared slides or through live samples suited for microscope viewing.

There are four main parts of the microscope. These are the ocular eye piece, the objective lenses, the adjustment knobs and the light source. The ocular eye piece is the part where the user observes the specimen, the objective lenses magnify the images, and the light source provides the light needed by the user to observe the specimen. The adjustment knobs help focus the lenses to attain a clear image. Different variations and improvements made to these main parts results in the formation of different microscope types we see today, primarily the light microscope and the electron microscope.

The most common and simplest type of microscope is the light microscope that requires a light source to use. Many light microscopes do not have its own light source, using a mirror to focus light from an external source to focus it on the image. More expensive models have a built-in light source that results into clearer images. This type of microscope is commonly seen in school and university laboratories or for other general applications outside the lab since they are easy to use and are affordable.