Gemina Laboratories Ltd. announced that its patented chemistry for Antibody Immobilization allows for a massive reduction in antibody usage when used in lateral flow assay (LFA) diagnostic tests. This represents the confirmation of a major technical milestone on the LFA format for Gemina. The Antibody Immobilization Platform allows for the reduction of test line antibody requirements by 75% vs.

standard physisorption, without impacting limit-of-detection. Gemina's Antibody Immobilization Platform creates a bridge (the Gemina Bridge) between a sensor surface and the antibodies stuck on that surface for target capture. Use of the Gemina Bridge results in optimized antibody usage and increased target capture activity per unit area of sensor surface.

Therefore, use of the Gemina Bridge imparts both significant performance advantages and significant manufacturing advantages with LFA tests. The industry standard antibody immobilization technique on nitrocellulose used in LFAs - non-specific physisorption, results in only 5-20% of the antibodies deposited on a sensor being "active" or capable of target capture. The Gemina Bridge rescues this lost antibody activity, meaning much less antibody is required to deliver the same test performance.

Laboratory Study: This massive reduction in antibody requirements was thoroughly demonstrated on the lateral flow assay test line with a COVID-19 rapid antigen test developed by Gemina Labs at the RAPIvD laboratories in Sharnbrook, UK. Instead of striping the antibodies directly onto the nitrocellulose (NC) strip, the Gemina Bridge is first stripped down to form a closely-packed monolayer, onto which the antibodies form a dense secondary layer with four times higher target capture activity than standard antibody-only test lines. Modeling Study: Dr. Robert Davies, an independent surface chemist expert, specializing in lateral flow assay development, was engaged by Gemina Laboratories to model the adsorption of the Gemina Antibody Immobilization Bridge to nitrocellulose, in comparison to optimal close packing of non-specifically adsorbed IgG antibodies.

Calculations support the creation of four times more antibody immobilization sites per unit of surface area with the Gemina Bridge, as highlighted in the above-linked white paper. In summary, the Gemina Antibody Immobilization Platform acts as a bridge between a sensor surface, in this instance the nitrocellulose test strip in a lateral flow assay, and the antibody used for target capture. Modeling data and internal experimental results indicate that use of the Gemina Bridge increases the density of active antibodies on the test strip by four times versus standard immobilization methods, meaning 75% less antibody is needed with the Gemina Bridge to achieve the same performance as a standard test.

This represents a massive savings in antibody consumption during test fabrication.