Speckled gold immunofiltration assay (DIGFA) assay

Summary

The spotted gold immunofiltration assay (DIGFA) is available as a clinical test.

Operation method

Speckled gold immunofiltration assay (DIGFA)

Principle

Spot gold immunodiafiltration assay is based on the spot immunodiafiltration assay, which uses colloidal gold marker instead of enzyme and eliminates the step of substrate color development. The test method is to nitrocellulose membrane (NC membrane) as a carrier, the reagent and specimen drops added to the membrane, through the percolation and gradual reaction. The whole process can be completed in a few minutes, and the positive result shows a red spot on the membrane.

Materials and Instruments

Cell Samples
PBS Tween-20 BSA Specific Antigen Gold Standard Antibody
Permeation unit NC membrane

Move

I. Reagents and materials
1. Filtering device: a small plastic box (4x3x0.6 cm) divided into two layers, a bottom and a lid, with a 0.5 cm diameter hole in the center of the lid. The bottom of the box is filled with highly absorbent bedding material, and under the hole in the lid, a piece of NC film is placed close to the bedding material. When the lid is closed tightly, it is a filtration device. Add 1-2 ml of specific antibody (primary antibody) or antigen to the NC membrane in the hole, dry naturally at room temperature, and store in a sealed plastic bag with desiccant.
2. Closure solution: Wash solution containing 0.2% BSA and 0.05% Tween-20.
3. Wash solution: 50 mol/L, pH 7.2 PBS.
4. Specific antibodies (primary antibodies) or antigens
5. Gold standard antibodies
II. Methods of operation
1. Remove the percolator and add 2 drops (approx. 100 ml) of containment solution, first on the NC membrane of the small hole;
2. Allow it to seep into the cassette and, on the NC membrane, add 1 drop (approximately 50 ml) of the specimen to be examined;
3. Allow it to penetrate into the cassette, and on the NC membrane, add 2 drops (about 100 ml) of washing solution;
4. Allow it to penetrate into the cassette, and on the NC membrane, add 1 drop (about 50 ml) of the gold standard antibody to react with the samples adsorbed on the NC membrane;
5. Allow it to penetrate into the cassette, and on the NC membrane, add 2 drops (about 100 ml) of washing solution;
6. Until the washing liquid has penetrated completely into the box
III. Observation of results
Positive reactions are considered when a red reaction appears on the NC membrane of a small pore; negative reactions do not color.

Caveat

1. The amount of specific antibody (primary antibody) or antigen, the specimen to be examined and the gold standard antibody must all be determined in advance by applying the square array method to determine the most suitable amount.

2. The padding in the bottom of the box should be highly absorbent, otherwise the results will be affected.

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/