Frequently Asked Questions Regarding Specific Proteins
To support our customers in the use of products from our specific proteins portfolio, we have collected the most frequently asked questions with related answers.
If your query is not included in the list below, please do not hesitate to contact us.
Q: How many tests per mL Q-product can I obtain?A: The number of tests that can be performed depends on the antibody dilution factor, the antibody volume per test and the dead volume of the bottle. The number of tests is often listed in the application note.
Q: How do I program the turbidimeters/nephelometers?
A: For the Q-products, CE-marked validated application notes for different instruments can be found here.
A general application note with guidelines for programming of other instrument is available here.
Dako can provide application notes suggested by the end-users. These application notes have not been tested or validated by Dako.
Q: How has the polyclonal antibody been purified?
The immunoglobulin fraction is prepared by salting out and ion exchange chromatography.
The elimination of bulk proteins gives a stable product with reduced background in gel precipitation techniques and minimal non-specific reactions in other applications.
Dako affinity-isolated antibodies are prepared by imunoaffinity chromatography, using antigens coupled to a solid matrix. The elution and adsorption techniques used, guarantee antibodies of high affinity.
Monospecificity of Dako polyclonal antibodies is obtained by the use of highly purified antigens for immunization. Traces of sometimes unavoidable, unwanted antibodies are removed by liquid or, in the majority of cases, solid-phase absorption. Crossed immunoelectrophoresis, with its high sensitivity and resolving poser, is included in our specificity controls.
Q: How often should I measure the controls?
A: It is recommended to measure the controls after each establishment of a calibration curve and after each run of samples.
If quality control results fall outside the range stated on the Analytical Value Sheet or outside the range established by the individual laboratory, recalibration is recommended.
Q: How often do I need to recalibrate?
A: For most antibody assays it is recommended to recalibrate
- When reagent lots change
- A new antibody dilution is prepared
- The antibody dilution is filtered
- Quality control results fall outside the range as established by the individual laboratory
- Every 28th day
Q: What does it mean when Dako says that their polyclonal antibodies have a fixed titre value?
A: A titre value is indicative of the activity of a polyclonal antibody. In Dako, the titre value for a polyclonal antibody is measured by single radial immunodiffusion (SRI). The SRI titre states how many milligrams of antigen which is precipitated in an agarose gel by 1 L of antibody.
The titre variation between batches of unconjugated polyclonal antibodies is less than 10%.