QuantiFERON–CMV is not available in the United States.
QuantiFERON–CMV is CE marked for commercial use in Europe


Search Results: Displaying all Human IFN-ɣ ELISA (7)

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Human IFN-ɣ° ELISA 2013 The QuantiFERON -CMV assay requires the use of the QuantiFERON -CMI ELISA to measure levels of IFN-ɣ. The procedure detailed in the QuantiFERON -CMV Package Insert for should be followed instead of the Package Insert for the QuantiFERON -CMI ELISA.
Do I test QuantiFERON -CMV plasma samples neat or diluted? 2013 If quantitative measurements of the IFN- ɣ (in IU/mL) are required for all samples, then you need to test the CMV and Mitogen plasmas neat as well as diluted 1:10 in Green Diluent. Therefore you need to allow for 5 ELISA wells per patient being tested. The ELISA is accurate for plasma samples containing up to 10 IU/mL. Use the neat plasma values if below 10 IU/mL, otherwise use the values from the diluted samples (multiplied by 10).
What is the stability associated with: a) Kit Standard? b) Conjugate 100X Concentrate? c) Wash Buffer? 2013 a) Reconstituted IFN-ɣ Standard may be kept for up to 3 months if stored at 2°C to 8°C (the date of reconstitution should be noted). Reconstituted IFN-ɣ standard should be equilibrated at Room Temperature (17°C to 27°C) for 1 hour before use. b) Once reconstituted, the Conjugate 100X Concentrate must be used within 3 months or discarded. Working strength conjugate (Conjugate 100X Concentrate mixed with Green Diluent) must be used within 6 hours of its preparation. Any unused Conjugate 100X Concentrate must be returned immediately to 2°C to 8°C following its use. c) Working strength Wash Buffer may be stored at Room Temperature (17°C to 27°C) for up to 2 weeks.
Can I use the QuantiFERON-CMI ELISA plates immediately after their removal from the fridge? 2013 No. Sealed ELISA plates should be allowed to equilibrate at Room Temperature for at least 1 hour before opening the foil bag.
Do I require an automated Plate Washer? 2013 No. Although an automated plate washer is recommended, manual washing can be performed following the procedure as outlined in the QuantiFERON-CMV Package Insert.
How important is washing during the QuantiFERON-CMI ELISA? 2013 As with most ELISAs, inadequate or incorrect washing is the single most common cause of QuantiFERON-CMI ELISA error. If you have any such problems, please check the following: • If bubbles and froth form during the wash steps, the flow rate of the wash cycle should be adjusted (usually lowered) to prevent this from occurring. • Wash volumes should allow the wash buffer to reach the top of each well (preferably with a positive meniscus forming over the rim of each well). • Ensure all wells receive sufficient and equal wash buffer. Blocked washer probes can be cleaned with a fine wire. • 6 complete washes are suggested as a minimum in the Package Insert, however additional washes can be performed without affecting the performance of the assay. • A soak period of at least 5 seconds between each cycle is recommended.
My results are not as I had anticipated. What could be the problem? 2013 General ELISA problems with the possible causes and appropriate solutions are listed below. NON-SPECIFIC COLOUR DEVELOPMENT: Possible Cause - Incomplete washing of the plate. Solution - Wash the plate at least 6 times with 400 µL/well of wash buffer. More than 6 washing cycles may be required depending on the washer being used. A soak time of at least 5 seconds between cycles should be used. Possible Cause - Cross-contamination of ELISA wells . Solution - Take care pipetting and mixing samples to minimize risk. Possible Cause - Components have expired. Solution - Ensure kit is used within the expiry date. Ensure that reconstituted Standard and Conjugate 100X Concentrate are used within three months of the reconstitution date. Possible Cause - Components are contaminated Solution - Avoid contamination of components HIGH BACKGROUND: Possible Cause - Incomplete washing of the plate Solution - Wash the plate at least 6 times with 400 µL/well of wash buffer. More than 6 washing cycles may be required depending on the washer being used. A soak time of at least 5 seconds between cycles should be used. Possible Cause - Conjugate reconstitution/dilution error Solution - Conjugate 100X Concentrate should be reconstituted with 300 µLof distilled water. Working strength conjugate is prepared by diluting the Conjugate 100X Concentrate 1/100 in Kit Green Diluent as per the Package Insert. Possible Cause - Incubation temperature too high Solution - Incubation of the ELISA should be performed at Room Temperature, 17°C to 27°C. Possible Cause - Components have expired Solution - Ensure kit is used within the expiry date. Ensure that reconstituted Standard and Conjugate 100X Concentrate are used within three months of the reconstitution date. Possible Cause - Enzyme Substrate is contaminated Solution - Discard substrate if blue coloration exists. Ensure clean reagent reservoirs are used. LOW ABSORBANCE: Possible Cause - Standard Dilution Error Solution - Ensure dilutions of the Kit Standard are prepared correctly as per the Package Insert. Possible Cause - Pipetting error Solution - Ensure pipettes deliver correct volume. Possible Cause - Wash Buffer dilution error Solution - Ensure a 1 in 20 dilution of the wash buffer concentrate is performed to prepare the working strength wash buffer. Possible Cause - Incubation Temperature too low Solution - Incubation of the ELISA should be performed at Room Temperature, 17°C to 27°C. Possible Cause - Incubation time too short Solution - Incubation of the plate with the conjugate, standards and samples should be for 120 +/- 5 minutes. The Enzyme Substrate Solution is incubated on the plate for 30 minutes. Possible Cause - Incorrect Plate Reader filter used Solution - Plate should be read at 450 nm with a reference filter of between 620 and 650 nm. Possible Cause - Reagents are too cold Solution - All reagents, with the exception of the Conjugate Concentrate, must be brought to room temperature prior to commencing the assay. This takes approximately one hour. Possible Cause - Kit / Components have expired. Solution - Ensure kit is used within the expiry date. Ensure that reconstituted Standard and Conjugate 100X Concentrate are used within three months of the reconstitution date. POOR STANDARD CURVE: Possible Cause - Incomplete washing of the plate Solution - Wash the plate at least 6 times with 400 µL/well of wash buffer. More than 6 washing cycles may be required depending on the washer being used. A soak time of at least 5 seconds between cycles should be used. Possible Cause - Standard Dilution Error Solution - Ensure dilutions of the Kit Standard are prepared correctly as per the Package Insert. DUPLICATE VARIABILITY: Possible Cause - Poor Mixing Solution - Mix reagents thoroughly by inversion or gentle vortexing prior to their addition to the plate. Possible Cause - Incomplete washing of the plate Solution - Wash the plate at least 6 times. More than 6 washing cycles may be required depending on the washer being used. A soak time between cycles should be used. Possible Cause - Inconsistent pipetting technique or interruption during assay set-up Solution - Sample and standard addition should be performed in a continuous manner. All reagents should be prepared prior to commencing the assay.

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