Hi,
My customer increased the primer concentration and got an additional peak (marked with the red square below) near the main peak. Would you kindly let me know what is the possible reason? Please see the image below. Thank you so much!
Hi,
My customer increased the primer concentration and got an additional peak (marked with the red square below) near the main peak. Would you kindly let me know what is the possible reason? Please see the image below. Thank you so much!
Hello,
While we do have a general idea of what might be causing this additional peak, we would be better able to support your customer if you could send the original data file (.mxp) in which these results were observed to qpcr@agilent.com<mailto:qpcr@agilent.com>.
Could you please forward this file?
Thank you,
Albert Grafsky
Manager,
Technical Services
Agilent Technologies, Inc.
T: +1 800 227 9770 | M: +1 858 229 1118 | www.agilent.com<http://www.agilent.com/>
F: +1 858 597 0619 | al.grafsky@agilent.com
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Hi qPCR support team,
I submitted a question on the community site, about an additional peak from Mx3000P. Following dear Albert’s suggestion, I send .mxp files.
The additional peaks appears in the file Jan 30 evening, 2019, well C1, D1, G1, F1.
The customer provided additional information. He is using a kit from a local vendor, and the qPCR reaction is set up as follows,
1. The 2 experiments, Jan 30 and Jan 30 evening, used same qPCR set up, difference is the anneal and extend time at 60℃. Jan 30 used 15s for annealing/extending, and Jan 30 evening used 30s.
2. Template. For both experiments (Jan 30 and Jan 30 evening), well A1, B1, E1, F1 used undiluted cDNA, while C1, D1, G1, H1 used 10X diluted cDNA as template.
3. Primer concentration. A1, B1, C1, D1 used 1ul primer, while E1, F1, G1, H1 used 1.25ul primer.
Sample Well
cDNA concentration
Primer volume
Anneal / extend time
Result
A1, B1 (Jan 30)
Undiluted
1ul
15s
C1, D1 (Jan 30)
10x diluted
1ul
15s
E1, F1 (Jan 30)
Undiluted
1.25ul
15s
G1, H1 (Jan 30)
10x diluted
1.25ul
15s
A1, B1 (Jan 30 evening)
Undiluted
1ul
30s
C1, D1 (Jan 30 evening)
10x diluted
1ul
30s
Additional peak
E1, F1 (Jan 30 evening)
Undiluted
1.25ul
30s
G1, H1 (Jan 30 evening)
10x diluted
1.25ul
30s
Additional peak
I agree that non-specific production formation possibilities increased due to template dilution, primer increasing, and annealing time increasing. Also increased extending time enables production of longer fragments. Correct?
Thank you!
Best regards,
Lin
Hi qPCR support team,
I submitted a question on the community site, about an additional peak from Mx3000P. Following dear Albert’s suggestion, I send .mxp files.
The additional peaks appears in the file Jan 30 evening, 2019, well C1, D1, G1, F1.
The customer provided additional information. He is using a kit from a local vendor, and the qPCR reaction is set up as follows,
1. The 2 experiments, Jan 30 and Jan 30 evening, used same qPCR set up, difference is the anneal and extend time at 60℃. Jan 30 used 15s for annealing/extending, and Jan 30 evening used 30s.
2. Template. For both experiments (Jan 30 and Jan 30 evening), well A1, B1, E1, F1 used undiluted cDNA, while C1, D1, G1, H1 used 10X diluted cDNA as template.
3. Primer concentration. A1, B1, C1, D1 used 1ul primer, while E1, F1, G1, H1 used 1.25ul primer.
Sample Well
cDNA concentration
Primer volume
Anneal / extend time
Result
A1, B1 (Jan 30)
Undiluted
1ul
15s
C1, D1 (Jan 30)
10x diluted
1ul
15s
E1, F1 (Jan 30)
Undiluted
1.25ul
15s
G1, H1 (Jan 30)
10x diluted
1.25ul
15s
A1, B1 (Jan 30 evening)
Undiluted
1ul
30s
C1, D1 (Jan 30 evening)
10x diluted
1ul
30s
Additional peak
E1, F1 (Jan 30 evening)
Undiluted
1.25ul
30s
G1, H1 (Jan 30 evening)
10x diluted
1.25ul
30s
Additional peak
I agree that non-specific production formation possibilities increased due to template dilution, primer increasing, and annealing time increasing. Also increased extending time enables production of longer fragments. Correct?
Thank you!
Best regards,
Lin