Our laboartory working in a diagnosis of Toxoplasma gondii using a Nest-PCR with pecific primers designed in a literature for amplified specific segments of B1 gene.
But my PCR work with contamination in a negative control (my reaction only with water), in that case I am observed a smear and when I amplified the other round of PCR with internal primers we obtained a specif product with the same band that positive control with specif DNA of Toxoplasma gondii. The smear we also obtained in a positive control, but we see the band around 200 bp, that correspond with the PCR product.
I alredy change all stocks including primers, water, Taq and dNTPs, but the smear in a negative control appear.
Other think is that negative control using second internal primers, always we obtained negative, without smear.
Can anyone help me.
PCR contamination
Started by fraga, Feb 08 2005 12:28 PM
1 reply to this topic













