Can I use samples with your kit which are not listed in the chapter “Intended Use” of IFU?
If you run samples for in-vitro-diagnosis, only the sample matrices listed in “Intended Use” are allowed and approved and can be used.
If you run samples for research applications, the kit might also be used for other sample matrices which are not listed in the “Intended Use” chapter (off-label use). For example, samples from different animals, tissue homogenates, cell culture or any other biological matrix. In this case, we would recommend contacting our product specialists in the lab (email@example.com ), who have a lot of experience in research applications. Beside this, we have also created an extensive list of publications where our kits had been used by the research community in different studies and research projects (available upon request).
Are there any recommendations and restrictions which the patient has to follow before the collection of the sample?
The patient should ask his medical doctor who will give him guidelines for the collection of the sample.
How many samples can be tested with the kit?
- Check the number of determinations on the cover sheet of the IFU ( )
- Check how many wells are needed for standards (STD) and controls (CTR) (double determinations are recommended) in the chapter “Materials, contents of the kit”.
- Start calculation.
The kit includes 6 STD and 2 CTR. This means, that 16 wells are needed for the calibration curve and controls.
96 wells – 16 wells = 80 wells = 40 samples in duplicates (or 80 samples in single determination)
Can I run the samples, controls, and standards in single?
It is recommended to run the assays in double determinations.
Why are the analytes acylated or methylated during the procedure?
The antibodies, which are used, do not recognize the natural occurring analytes directly – but the modified (acylated or methylated) analyte. This additional chemical modification of the analyte as part of the sample preparation makes the assays more specific.
Do I receive my shipment cooled? And how should I store the kits after receipt of the shipment?
No, LDN ships its goods at ambient temperatures without cool packs for a maximum of 1 week. For this period, the kits and reagents are stable. Upon receipt, the kits have to be stored as stated in the IFU and on the labels.
How should I store the kit?
Upon receipt of the goods, they should be stored according to the IFU, chapter “Storage and Stability”, which is at 2–8 °C.
How are the samples stored?
Please refer to the IFU, chapter 5 “Sample collection and Storage”.
What kind of instruments are needed to run the assays?
Please refer to the IFU, chapter 4.2 “Additional materials and equipment required”.
Should I use an automated plate washer?
The washing steps can be performed manually – but an automated plate washer is recommended as it guarantees more constancy in the washing procedure.
What type of plate reader do I need?
The reader must be capable to read absorbances of 96 wells microtiter plates at a wavelength of 450 nm (in some cases a reference filter of 620–650 nm would be preferable but not mandatory).
Can I use reagents from different kits with different lot numbers?
Please refer to the IFU, chapter 2.1 “Precautions, guidelines and warnings”. In general, it is not possible to mix reagents from different lots.
What kind of curve fitting should I use?
Please refer to the IFU, chapter 7 “Calculation of results”. In general, the usage of a non-linear regression method such as the 4-parameter curve fit is must be used.
How can I calculate the results if I don’t have a curve fitting program/software?
There are different providers who offer online calculation programs for free. Please contact us at firstname.lastname@example.org – we will be able to send you addresses of useful websites.
The ODs decrease with increasing concentration of the analyte. Is this correct?
Yes, that’s correct. Our assays use competitive methods for the quantification of analytes. This means, that the OD decreases with increasing concentration of the analyte. Example:
Can I run the assays automated on an open ELISA processor?
For in-vitro diagnosis, our assays have been validated with manual procedures. Automated procedures on open ELISA processors (Gemini, Evolyzer, etc.) are possible. For details, please contact email@example.com.
Is my research sample suitable for a certain biogenic amine assay?
The most important question is: what is the concentration range which you expect? If the expected range falls within the measuring range of the assay, the chances are good that you can quantify your analyte. After checking this, you should start a small proof-of-principle with a dispensable control sample.
Do you have an overview, which animal species or biological sample such as homogenates, work with your assays?
For details and for recommendations for your specific protocol please contact firstname.lastname@example.org.
If I do not use the tissue immediately, how can I store it?
The tissue should be frozen directly without any additives in liquid N2 and then stored frozen as cool as possible (-80 °C is preferred). Thawing should be performed as quick as possible and if advised, the addition of stabilizing buffers is recommended.
Do the Biogenic Amines assays contain components based on recombinant origin (viral or bacterial)?
No, recombinant components are not used in these assays.
After adding Substrate to the wells, which color should develop?
The TMB-substrate turns to blue.
Will the addition of the Stop Solution change the color of the Substrate?
Yes, the addition of the Stop solution will change the blue color to yellow.
The results I receive are higher than the highest standard. How should I handle this?
Please refer to the IFU. There is a chapter where it is described how to proceed with sample concentrations higher than the highest standard. In most cases it is advised to dilute the sample with zero-standard (or water) and re-assay.
Do I have to multiply my results with a dilution factor?
Please refer to the chapter “Calculation of Results” in the IFU. When required, the dilution factor is indicated. In all other cases only the additionally diluted samples must be multiplied with the corresponding dilution factor.
Are there external quality assessment (EQS or proficiency testing) schemes for your parameter where you participate?
Yes, we participate at different institutions with different parameters:
INSTAND: Adrenaline, Noradrenaline, Dopamine, Serotonin, 5-HIAA, Metanephrine, Normetanephrine
FAPAS: Histamine in fish
RfB: Chromogranin A