DNA Standard - DNA Standard for Calibration of spectrophotometer (Mar/23/2007 )

We have recently started doing Real Time PCR using ABS 7300 system for GMO detection in Soy Lecithin etc. We want to check quality (Purity and concentration ) of DNA extracted ( Promega Wizard Method.) with a Shimadzu -UV1601 spectrophotometer. For clibration of spectrophotometer , we need suitable DNA standard . Please guide me as to which DNA standard will be most suitable ( Should it be single stranded or double stranded ?) .I dont know whether the DNA extracted by us is single or double stranded .

S.Kumar

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Ok, first of all, what are your samples? Is it RNA or DNA? If it's RNA, then it is single stranded by nature, but if it's genomic DNA or plasmid DNA, then it is double stranded. In the case of real time PCR, usually SYBR green is the most popular binding dyes that binds to any double stranded DNA. So if your samples are RNA, u must convert your samples to cDNA,then only u can run your samples for real time exp, eg: standards,testing samples, etc. I think, for starters, it is better for u to use any double stranded DNA, eg plasmid or gDNA to prepare your standards. Gd luck..

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Dear Sir,


Thanks for your reply. Ours is Genomic DNA from IRMM Soy/Soy Lecithin .This means it is double stranded . I will look for suitable DS DNA standard now. I plan to go for following sigma DS DNA standard:

D8515
Sigma Deoxyribonucleic acid−cellulose double-stranded from calf thymus DNA (lyophilized powder ) .Hope this will serve my purpose.

s.kumar

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