RAPTOR - Portable, Multianalyte Bioassay Detection System

This rapid, automatic fluorometric assay system is a portable (6.45 kg) 4-channel system for monitoring toxins, viruses, bacteria, spores, fungi and other diverse targets. An extremely reliable third-generation product introduced in 2000, users have found these instruments will operate for two years or more with no breakdowns or leaks, and that they will tolerate debris-laden samples (such as are produced in mailrooms and food processing facilities) - impressive feats for a fully automated wet assay system.

The completely self-contained instrument is the culmination of a careful integration of optics, fluidics, electronics, and software into one compact system for laboratory and field assays. It performs user-defined, multi-step, assay protocols for monitoring fluorescently-labeled chemical reactions occurring on the surface of each of the system's four disposable optical waveguide sensors. Toxins and bacteria such as ricin and B. anthracis have been detected at levels below <1.0 ng/ml and 100 CFU/ml, respectively. Disposable assay coupons for these and many other targets are now being offered for sale. Please email or call (360-805-4930) for a quote.

The following table presents sandwich assay sensitivity data gathered from researchers worldwide who have used our equipment with a variety of raw fluid samples. Sensitivity levels may vary significantly depending on many factors, and the table is presented for reference purposes only. Please refer to the attached bibliography for further information on waveguide processing and sampling methods, or contact Research International.

• Download the RAPTOR data sheet(119 KB)

Footnotes:
(a) Private communication - G.P. Anderson, Naval Research Laboratory.
(b) Unpublished data - David McCrae & Ann Wilson, Research International.

• A=Analyte 2000 publications
• E= Evanescent wave publications
• R= RAPTOR publications

How It Works

Research International's biosensor systems are based on monolayer receptor-ligand reactions taking place on the surface of injection molded polystyrene waveguides. All fluidic and optoelectronic steps associated with the assay are performed automatically. The baseline protocol used to identify specific pathogens is the 'sandwich format' fluoroimmunoassay. In a typical waveguide-based sandwich immunoassay, the cylindrical waveguide has a monolayer of capture antibody immobilized on its surface as shown in Figure 1. Such factory-coated waveguides will maintain activity for a period of months if stabilized and not subjected to high temperatures.

Figure 1: Optical and biochemical processes associated with a waveguide bioassay.

At the time of use, the waveguide is first incubated with the fluid sample for three to five minutes. After a wash step, the waveguide is incubated with fluorophore-labeled antibody for three to five minutes to form an antibody/antigen/labeled-antibody sandwich. These molecular sandwiches generate an optical signal when excitation light is injected into the waveguide. The excitation light creates an electromagnetic 'skin effect' in adjacent fluid and it is this so-called evanescent wave electric field that excites bound reporter molecules to fluoresce. As a final step, individual molecular signals are collectively coupled into the waveguide and monitored with a sensitive photodetector that looks down the waveguide axis.

A major problem with evanescent-excited fluoroimmunoassays has been low excitation efficiency. Light injected into a waveguide is most effective at exciting surface-bound fluorophores if the light's propagation angle is near the condition of total internal reflection (TIR) at the waveguide surface. Research International has discovered and patented a novel aspheric dielectric structure that injects light into the waveguide in such a way that evanescent electric field intensities are at near-theoretical limits. This structure, the waveguide and a signal collection lens are molded as one component, providing a highly efficient, low cost, and compact optical sensor element.

Coupons

Four of the waveguide sensors are mounted in a disposable plastic coupon (see Figure 2), allowing four different pathogens to be detected in a sample; or multiple channels may target the same pathogen to improve statistical certainty. An elastomer needle septum connects RAPTOR™ fluidics with fluid distribution channels molded into the coupon's body. In addition to providing controlled flow over the optical detectors, an assay recipe identification system is incorporated that automatically reads a coupon bar code when the coupon is mounted into the RAPTOR™ instrument. This bar code identifies the type of assay to be run by the instrument and allows very sophisticated assays to be performed by unskilled persons. A computer embedded within the RAPTOR™ performs and controls all steps in the assay procedure.

Figure 2: RAPTOR™ bioassay coupon.

Assay Procedure/Specifications

To begin an assay, a coupon is inserted into a docking bay in the instrument's top surface. RAPTOR and coupon optics and fluidics are automatically connected when the compartment's door is closed. The user performs an assay by turning the instrument on and pressing the Run button. During the assay, a timer in the LCD display window provides time remaining until completion. On completion, assay results for the four channels are displayed.

Behind the scenes, an onboard computer reads the recipe code on the coupon, primes the coupon for flow and controls fluidics and optoelectronic steps during the assay. All fluids needed to perform an assay, with the exception of sample, are contained in the unit. Buffer and reagent are contained in flexible on-board pressurized bags, and waste in a third unpressurized bag. The reagent bag is housed in a phase-change module that keeps the reagent at a temperature of 30°C or less, preventing deterioration of any thermally sensitive reagents.

Table 1 is a summary of system specifications. The instrument package provides a backlit six-key keypad and a four-line LCD readout. The unit can talk, control, or be controlled by other instrumentation via an RS-232 channel or RF links accessed through a connector in the instrument's battery compartment. A second connector that can supply DC power to and digitally control ancillary electronics is also provided. The unit incorporates a one-megabyte nonvolatile flash memory that can store a large number of assay protocols as well as a step-by-step log of each assay performed. An on-board BA-5590/U battery provides power for 9 to 24 hours of continuous operation depending on the backlighting intensity selected. With the battery installed, overall unit weight is about 14.2 lbs (6.45 kg), and the unit's size is 11.0" W x 7.95" H x 7.29" D.

Table 1: RAPTOR™ System Specifications

Characteristic	Description
Use Profile	Indoor/outdoor sample collection, transfer, and assay; storage of 63 assay recipes; user in full MOPP gear either walking or in a slow-moving vehicle.
Physical Size	28 cm L x 17.3 cm W x 20.5 cm H.
Weight	6.45 kg with battery, 5.6 kg without battery.
Operating Temperature Range	1 to 35°C
Storage Range	-29 to 66° C
Assay Coupon	Four simultaneous assays; disposable; bar coded for assay identification.
Fluids Handling	Bi-directional, multi-channel peristaltic pumps. Sample may be oscillated to lower assay time; reagent recovered.
Fluids Storage	On-board buffer and reagent storage. Reagent stored in reusable phase-change module to limit peak temperatures.
Sensitivity	Dependent on analyte; 1 – 10 ppb typical.
Photocurrent Resolution	0.02 pA; 12-bit A/D.
Dynamic Range	1:106 (0.02 to 22, 500 pA)
Assay Time	Dependent on assay, 10– 15 minutes is typical.
Data/Command Entry	Day/night visible keypad and display; usable in MOPP gear.
Visual/Audible Output	Liquid crystal display provides positive/negative/retest; identity of agent.
Communication	RS-232 bi-directional serial link and RF telemetry capability via optional BioLink™ RF Data Radio.
Data Storage	EEPROM retains raw or processed data for 100 assays.
Batteries	8-hr continuous use; primary battery BA-5590/U, 1.05 kg (2.3 lb).
Power Consumption	7.2 W, nominal
Survivability	MILSPEC 810-E
Humidity	20 – 90%, noncondensing.
Ancillary Equipment	Nylon twill photographer’s-style carrying case with storage for assay accessories; carry strap compatible with MOPP gear.
Accessories Support	Software control of SASS ® 2000 air sampler for sample collection and sample input.

Features and Benefits

Waveguide-based fluoroimmunoassays have many features to recommend them. Although similar in some ways to traditional ELISA protocols, they are much faster and comparable in sensitivity: Typical assay times of 10-15 minutes are possible because pathogen targets are reacting with exposed monolayer-thick reaction layers. Since waveguide capture layers target a single or very narrow range of pathogens, sensor coupons may be reused if test results continue to be negative. This may very favorably lower cost per assay, since in many survey applications most assays will be negative.

In a lab setting, assay sensitivity was unaffected by 30 consecutive negative assays performed using clean samples. While field results may vary, the waveguide sensors are remarkably insensitive to sample contamination and have been successfully used with urine, whole blood, milk, marine water, 10% meat slurries and slurries of human waste. In addition, bacteria captured on the waveguide surface are still viable, and the system can serve as an affinity capture surface for later confirmatory analyses and chain-of-custody needs.

The RAPTOR fiber optic biosensor system represents a significant leap in technology that is capable of real time detection of microbial pathogens with or without conventional culture. Furthermore, the biosensor is a compact, portable system that can easily be adapted with flow-through devices for on-line monitoring of water systems. This technology can also be adapted to quantitation of all microorganisms against which a specific antibody can be made. As new pathogens emerge the biosensor can be adapted to signal their presence. Unlike many recent developments in microorganism detection, which represent minor improvements over current technology, an immunoassay-based biosensor for real time or near real time detection of microbial pathogens represents a pivotal advance in scientific technology.

Safety Act 2002 Approved Product

Application Areas:

• Water quality monitoring
• Laboratory testing
• Food safety monitoring
• Medical
• Agriculture
• Environmental
• Homeland security
• Mailrooms
• UAV's (Unmanned Aerial Vehicles)

Features:

• Compact, portable system (about the size of a car battery)
• Immunoassay-based biosensor for real time or near real time detection of microbial pathogens
• Typical assay times of 10-15 minutes
• Coupons may be reused if test results continue to be negative.
• Successfully used with urine, whole blood, milk, marine water, 10% meat slurries and slurries of human waste.

More information:

• RAPTOR Frequently Asked Questions
• RAPTOR Parts and Accessories page (photos and part numbers)
• Product bibliography
• RAPTOR Technical Report (please contact us: info@resrchintl.com)
• RAPTOR specifications (119 KB)
• RAPTOR Assay Coupon Product Bulletin (295 KB)
• Candidate Disinfectants for Research International Products (978 KB)
• Bluetooth Biolink™ Wireless Units provide plug-and-play wireless communication between any Research International product and a remote PC or laptop (174KB).

Contact Us:

• Call Toll Free at 1-800-927-7831

• Send E-mail

• Or Request a Quote

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