Sanger sequencing is longer than amplicon?

More Zhenyu Shen's questions See All

use a RNA fragment to construct a standard curve for a RT-PCR?

Can I use a synthesised RNA fragment containing the amplification target to construct a standard curve for a one-step RT-PCR? Can I also use the RNA fragment as the amplification control? What...

03 April 2019 3,907 5 View

Sequence LNA PCR product?

I am doing genotyping PCR. The probe has 3 LNA nt. Can I do regular Sanger sequencing to the PCR product to verify the genotype?

10 November 2018 9,469 0 View

A short amplicon got a long sequence by Sanger sequencing?

By PCR I got a ~500 bp amplicon from a microorganism. I did gel purification and sent for Sanger sequencing with the PCR primers from both ends. Now the sequencing result from the forward primer...

05 June 2018 3,067 3 View

Primer and probe TM of one-tube real-time nested PCR?

I am designing a one-tube nested real-time PCR. Only one probe will be used and the signal will be only collected from the second stage. Any suggestions for primer and probe TM design?

04 May 2018 7,312 5 View

One primer specific?

I am designing a Taqman PCR. However, I only can find a small continue specific fragment (9bp) in the target region. How should I design primers and probe? 1. place the 9 bp in either forward...

04 May 2018 8,765 6 View

QPCR amplicon did not have the band on the agrose gel

I did a QPCR, which gave me the CT around 20 and it had a sharp peak around 80 degree according to the melting curve. Then, I realized I need to extract DNA from it. So, I ran i5 ul of the 25 ul...

07 August 2017 8,542 3 View

Dose SYBR Green change amplicon running speed in an agrose gel ?

As mentioned in the title, has someone compared the running speeds between SYBR Green-DNA polymerase - amplicon and conventional polymerase -amplicon in an agrose gel?

07 August 2017 4,883 1 View

Forward sequencing and reverse sequencing have different results

I have a ~700 PCR amplicon sequenced from both directions. However, forward sequencing and reverse sequencing have different results. The forward one has almost perfect matches with existing...

06 July 2017 6,835 4 View

How to find a genus or species specific gene for diagnosis?

For example, I know a bacterial genome. How should I search the genome with all bacterial genomes to find out a specific segment which can be used in PCR to diagnose the presence of the bacterium...

31 December 2016 3,945 4 View

How do you search primer specificity?

BLAST primer, ipress, MFEprimer ? which one do you use?

31 December 2016 2,476 0 View

Can I base on reverse DNA sequences to perform alignment, convert to amino acids and GenBank submission?

I have reverse sequences (AB1 format), can I base on reverse DNA sequences to perform nucleotide alignment, convert nucleotides to amino acids and deposit the sequence in GenBank database?

11 August 2024 5,138 1 View

Does anyone know what might be causing the smeared bands on my western blot?

I got these smeared bands quite often lately. We typically run the gel at 140V with a 10-12% gel and do a wet transfer at 220 mA for 1.5 hr in cold room. We also noticed some dirty spots/dots (see...

10 August 2024 7,480 3 View

How to confirm the site-directed mutagenesis result without performing NGS?

I'm cloning a fragment of 3200 nts into plasmid. The cloning was successful, however, 02 amino acids were mutated. Now I want to fix these 02 aa by site-directed mutagenesis technique using...

08 August 2024 4,645 2 View

Why is my ASO degraded quickly on agarose gel?

I have been working on Red blood cell-derived extracellular vesicles as Antisense Oligonucleotide (ASO) carriers. We normally run agarose gel to quantify the loading efficiency. I used naked ASO...

06 August 2024 3,130 2 View

Low-yield gel extraction problem?

I am having an issue with my gel image where my PCR product is not appearing very bright on the gel. When I perform gel extraction, the A260/280 purity value is very low. I used the Qiagen gel...

05 August 2024 9,798 3 View

Does anyone have issues using Prepman Ultra reagent for MicroSeq ID bacterial, fungal and yeast sample preparation?

I have been attempting to extract DNA from Bacterial, Fungal and Yeast banked samples (>1e7 cells) using Prepman Ultra reagent and I seem to be struggling to obtain a sequence. Although the...

01 August 2024 2,079 0 View

I'm optimizing a tetra-ARMS PCR protocol with amplicon sizes: 165bp, 123bp and 93bp. Why, in the gel, only 165bp is visible while I'm expecting all 3?

It's an end-point PCR protocol. I'm using 1.5% agarose gel with SyBR Safe dye and TBE as a running buffer, visualization on BioRad XR+ system. I was primarily thinking of primer efficiency,...

01 August 2024 4,673 4 View

PCR showing no bands - Master mix and primers didn't mix?

Hello everyone, I performed a PCR yesterday, and the results showed no bands on the gel. Of course, I probably missed some crucial steps, like adding my samples to the PCR strips themselves, for...

31 July 2024 2,406 6 View

How to check pH of a high strength hydrogel?

We are working on biopolymeric hydrogels. Our system is highly viscous and sticky, and the gel formed are high in strength. We are unable to use pH electrode and pH strip. Please suggest an easy...

30 July 2024 942 2 View

How to retain amplicon yield after Ampure bead cleanup, following a 2-stage PCR protocol?

Hello all, I have been trying to follow a 2-stage PCR protocol used to amplify barcodes of a large yeast library, as per Nyugen et al. (2022) -...

30 July 2024 841 2 View

Kevin Cavallin

Could you post a copy of your chromatogram?

When I've seen this issue in the past, it's usually when the signal-to-noise ratio is low, and the base calling software erroneously makes base calls off of elevated background noise. Any chance you have a contaminant migrating with your sample?