Rapid Tagged Protein Assay Kits
Protein tags are a useful and convenient tool to improve the solubility of recombinant proteins, simplify protein purification and detection, and allow protein localization during protein expression and purification. In live cells, protein tags can be used in tracking proteins directly by microscopy or indirectly by western blot, immunoprecipitation, or immunostaining. In general, protein tags consist of several to hundreds of amino acids, and small protein tags have not so much influence on the fusion protein as large protein tags. These tags are fused with the target gene and expressed with a recombinant protein at either the N-terminal or the C-terminal.
Amerigo Scientific offers single-use lateral flow immunoassay (LFA) kits for rapid, easy detection of tagged proteins in protein expression and purification systems. Our kits use LFA strips coated with gold-conjugated antibodies targeting to the specific tag to provide semi-quantitative detection within 10-15 minutes. These rapid detection kits can be used to detect tagged proteins directly from cell culture media or cell lysates without any special instrumentation or handling.
Rapid Detection Kits
Features of Rapid Detection Kits
- Easy-to-use lateral flow strips for the detection of desired tagged proteins
- Qualitative results within 10-15 minutes
- Sensitive detection of protein tags as low as ng/mL in supernatant or cell lysate samples
- Specific assay without cross-reaction with common lysis and protein preparation reagents
- Reliable results similar to other antibody immunoassays, including western blot and ELISA
- Long shelf life of one year
Assay Principles of Rapid Detection Kits
Our kits are either competitive or sandwich lateral flow assays designed to detect commonly used protein labels. The kit contains assay strips and diluents. Each assay is performed by simply adding a properly diluted tissue culture supernatant, lysate, or purified protein sample to a lateral flow strip.
In the sandwich lateral flow assay, gold-conjugated capture antibodies against the specific tag are embedded in the conjugation pad of a strip. Detection antibodies that can bind the specific tags are immobilized in the test line, and secondary antibodies that can be recognized by the capture antibodies are immobilized in the control line. After applying a sample to the strip, the capture antibodies bind to the specific tagged proteins in the sample as it flows through the membrane. An antibody sandwich is formed at the test line, producing a red line of positive results. If no test line appears, it indicates that the sample does not contain the specific tagged proteins or the concentration of tagged proteins in the sample is below the detectable level. The visible appearance of test line and control line indicates the presence of the specific tagged proteins in the sample.
In the competitive lateral flow assay, proteins with the target tags are immobilized in the test line on the membrane strip. Gold-conjugated capture antibodies specific to the target tags are embedded in the conjugation pad. The second antibodies that can be recognized by the capture antibodies, are immobilized in the control line. If no specific tagged proteins are present at detectable levels in the sample, the capture antibody will bind to the tagged proteins embedded in the strip and form a red test line, representing a negative result. If the sample contains target tagged proteins, the capture antibodies will bind to the tagged proteins in the sample and not to the immobilized tagged proteins. The concentration of the tagged proteins is inversely related to the color intensity of the test line. As the concentration of the target tag in the protein sample increases, the color intensity of the test line decreases or even disappears.
Principles of competitive LFA and sandwich LFA
.
