Observation |
Problem |
Corrective Action |
No signals on positive control spots |
Concentration of detection antibody and/or SA-HRP too low |
Use concentration/dilution specified |
Chemiluminescent reagents failed |
Repeat with fresh chemiluminescent reagents according to manufacturers protocol |
Inadequate exposure time to film |
Increase exposure time |
No or low signals on target spots |
Sample dilution too high |
Use more sample |
Analyte abundance in sample is low |
Use more sample |
Use different cell line |
Verify that conditions used to stimulate cells were optimal |
Sample deteriorated during preparation |
Supplement buffers with protease and phosphatase inhibitors where indicated |
Sample deteriorated during storage |
All samples should be stored at ≤ 70 °C. |
Avoid freeze-thaw cycles |
Inadequate exposure time to film |
Increase exposure time |
Signals on negative control spots |
Concentration of detection antibody and/or SA-HRP too high |
Use concentration/dilution specified |
Sample concentration too high |
Use less sample |
Uneven or high background on blank areas of array |
Insufficient washing |
Perform number of washes with volume indicated as specified in the product insert protocol |
Perform washes in large container and not the 4-Well Multi-dish |
Concentration of detection antibody and/or SA-HRP too high |
Use concentration/dilution specified |
Array was allowed to dry out partially during the procedure |
Always keep arrays submerged. Minimize time the array is exposed to air. |
Creased or scratched arrays |
Use flat-tipped forceps to handle arrays on array number. |
Too many spots have signals |
Insufficient washing |
Perform washes as stated in product insert. Perform washes in a large container, not in the 4-Well Multi-dish. |
Concentration of detection antibody and/or SA-HRP too high |
Use concentration/dilution specified |
Sample concentration too high |
Use less sample |