Operating Principles
Saigene's near-real-time analysis system performs sandwich hybridization assays (SHA) using an automated processor instruments with single-use kits of assay components. Each type of kit analyzes one specific set of target organisms that might be contained in field samples, such as sea water (for HAB identification), source water used in oil well completion, or heavy brines that accompany crude oil from a producing well.
Specimen acquisition, sample preparation, SHA, reading the results by eye or instrument.
The procedure begins with a field specimen that may contain organisms of interest. First, the operator prepares the specimen for analysis, such as filtering it, in order to concentrate the target organisms if they are present. Then the operator applies a lysis agent to break down any cells contained in the sample. This lysate provides the sample used in the SHA reaction series.
Sandwich Hybridization Assays (SHA)
SHA uses an immobilized molecular probe to capture target biomolecules from lysed cells contained in an original specimen
The sandwich assay performs serial reactions to build up a molecular chain, or "sandwich" layers, ending with
In the final step, horseradish peroxidase (HRP) reacts with TMB to produce a blue color in the last row of microtiter plate wells.
Physical Format
Our SHA implementation uses a set of 12 finger-like prongs coated with capture agents. Each prong may have a different capture agent, or some assays may take advantage of redundancy. The prongs dip into a row of wells in a 96-well microtiter plate positioned below the prong strip.
In our system, the processor moves the set of prongs from one row of wells in a microtiter plate to another, building the reaction sandwich until the reporter dye is ready to read.
The prong-in-well design inverts the more common method of well coating and reagent pipetting used in immunoassays. Our design eliminates the cost and complexity of robotic pipetting by only having to move a multi-pronged "dipstick" from one row of wells to another. At the end of the assay, the only disposable components are the prong strip and the microtiter plate.