Basic High Throughput Screening Equipment, Part three

In this final entry in our series, we'll take a look at liquid handling equipment and miscellaneous tools.

LIQUID HANDLING EQUIPMENT

There is a huge diversity in the number of liquid handling equipment options that are available today. Most well known are the hand-held manual pipettes, so we'll skip going into detail about those. Worth noting are advanced automated pipette setups. Automated setups are scalable to a lab's needs, and the measurements and recording equipment used are incredibly helpful in replicating exact conditions for each new set of assays.

Popular liquid handling setups are numerous, so we'll take some time here to examine the most popular. Solenoid valve-based liquid dispensers use pressurized fluids, robotic equipment and a swift valve to quickly deliver material to microplates. Simultaneous dispersion is possible with this system, and it is best suited for detection reagents, cell media and buffers. Peristaltic pump-based dispensers use pumps, flexible tubing and rollers to move fluids. Cassettes (which house tubing, tension adjustment, tips, plastic housing and adjustment screws) used in the pump-based dispersion process are interchangeable and prized for their out-of-the-box accuracy. Unfortunately, their expensive replacement cost make this a costly option.

Pintools are usually only used for low-volume, fixed microplate transfers, such as moving compounds to the microplate arrangement from the library. Pintools are reusable, but they do need to be washed and dried before every use. Configurable and customizable, these see a variety of applications. Acoustic dispensers utilize concentrated sound energy in bursts that dispense 1-10 nL droplets without direct contact. These are notable for their accuracy and quickness, as well as a lack of contamination risks. The acoustic dispenser is able to effect separate concentration levels from a single stock. This is an incredibly versatile and configurable tool. However, it is known as one of the most expensive options, and its speed is often negatively contrasted against that of the pintool.

MISCELLANEOUS TOOLS

Hoods, Freezers and Incubators

Available in a wide variety of sizes, styles and setups, it's best to base selection of this equipment on both high throughput equipment demands as well as general laboratory needs. Here again, you should speak with any vendors and engineers or scientists with previous high throughput equipment experience for advice and direction.

Other Equipment Considerations

Once the basic high throughput screening equipment has been set up in the lab, it's a good idea to update safety measures and look into additional equipment. Specialized tools, such as pH meters, electronic balances and spectrophotometers, that will complement currently installed high throughput equipment are recommended. Again, speak with your vendor for further direction.

Basic High Throughput Screening Equipment, Part Two

In this article we'll continue our examination of basic highthroughput screening equipment. We'll begin by completing our look at various microplate reading equipment, and continue on to handling equipment.

MICROPLATE READERS, CON'T

Both monochromators and filters offer separate and distinct advantages. Filters are comparatively less expensive (allowing several to be maintained at  the same time)and are capable of efficient division of wavelengths and excitations. However, repeated equipment updates and the inability to perform spectral scans are notable flaws.

It's also important to consider any incubation and long-term temperature control needs that you might have. Modern microplate readers offer equipment designed to address these needs, as well as further tools to handle reagent injection, gas purging, and customizable top/bottom reader layouts. There are also several specialized high throughput, high content scanners worth considering because their specific applications. High content imagers utilize automated equipment and processing software to collect high volumes of data under customizable parameters. Laser scanning cytometers are notable for their use of lasers to excite microplates, an effective method for detecting cells, model organisms and colonies. Finally, label free detection is an exciting new development in the world of high throughput screening, but we'll reserve the details for another article.

MICROPLATE HANDLING EQUIPMENT

Most laboratories prefer to use automated microplate handling equipment. However, there are still partially automated options available for the budget-conscious. In order to decide which setup will work best for you it's a good idea to consider the average number of plates you expect to process each day, the volume you expect to handle, as well as the speed and accuracy expected in returning results, the amount of space that's available in the lab, software needs and any anticipated future upgrades.

ADDITIONAL

Once you've determined which microplates and microplate readers will best suit your needs be sure to consult with an expert regarding microplate sealing systems and materials, as well as monochromators and filters. Reliable sealing equipment will help maintain well conditions over the course of multiple assays, allowing for the quantification and recording of conditions, exposure length and contamination risks. Automated sealing systems are currently available as well. Monochromators and filters are used in wavelength selection. Optical filters are incorporated and used in emission filtering and excitation. Generally the microplate reader you select will have an approved option that's been recommended by the vendor. Many of the most popular readers are modular, making them highly versatile and customizable depending on a given laboratory's needs.

Basic High Throughput Screening Equipment, Part One

There is an incredible selection of equipment available to laboratories that want to utilize high throughput screening. This series of articles will take a look at the basic equipment needed for these procedures.

In order to utilize basic high throughput screening processes, at a minimum a facility will need the following equipment: hoods, freezers, incubators, liquid handling equipment, microplates, microplate readers, microplate handling systems, as well as some miscellaneous equipment which we will discuss later on. Organizing your desired equipment list will help you work with investors to ascertain a feasible budget and will help you decide upon installation particulars. However, if this will be the first time you work with any or all of this equipment, it's highly recommended that you speak with engineers or scientists who have previous experience with the equipment. It's also a good idea to consult with vendors for direction and specific pricing needs.

MICROPLATES

Today microplates are considered a standard tool in bioassay automation and miniaturization. These come in a variety of sizes, materials and colors, each of which is designed to best suit the needs of a variety of different environments. Most organizations generally use microplates with 96 wells, with a capacity that nominally falls between 250-300 microlitres. Some of the most common microplate materials are cyclic olefin copolymer, which is best suited for use in acoustic droplet ejection; polypropylene, which is often used for thermal stability; and polystyrene, which is often seen as a low-cost alternative to other materials.

MICROPLATE READERS

Microplate readers utilize light-sensitive detection technology to take measurements. A wide variety is currently available and often numerous configurations are used in conjunction with one another in order to take multi-purpose measurements. Popular technology includes luminescence and fluorescence intensity. Generally the setups are divided into mutli-mode and single mode readers. Single mode microplate readers are generally seen as more cost-effective and are used in smaller labs. Multi-mode readers are generally used for more specialized needs.

There currently exists a number of microplate readers designed with distinct detection technology, for use in certain labs. Fluorescence polarization, which measures florescent molecule mobility, and time-resolved fluorescence, which measures fluorescent molecule emissions, are two of the most notable. Absorbance, which measures light as it travels through the well, is used in the detection of light absorption. Luminescence measures light generated in biochemical and chemical reactions and is popular for use in gene expression assays, ATP detection and cytotoxicity assays. Another reader worth noting is AlphaScreen, used to study bimolecular interactions through the measurement of molecules under excitation.