Some times even if we doesn,t got a band in agarose gels for DNA we will get its concentration and purity suitable for downstream process while checking it in bio photometer; So Qualitative or Quantitative parameter should be followed for PCR amplification of SSR Molecular marker systems?
I am not sure I truly understand your question, but I will give it a try: A260/A230 measure contamination of your DNA samples by aromatic solvent, such as phenol (it also detects guanidium thiocyanate). As for A320, I have no clue... I know of A260/A280 which gives an idea of contamination by proteins or amino acids. Then, if your sample is degraded (small DNA fragments) or contains only the dNTPs / the template used for PCR, detection by spectrophotometry will give you a concentration, it does not distinguish between polymerized and free DNA bases. That's why you can have a "DNA concentration" value but no band on agarose gel. Hope that'll help!
Hi! Binoy,
My sincere advise when ever you isolate DNA need not go for photometric readings for quantification. Though it is a bit tedious go for gel check that is always advisable. I do that always, you come to know whether your DNA is intact or degraded. In general the ratios tells purity of DNA. 260/280 should be around 1.8 then your DNA is pure. If you get higher reading protein contaminated or less value RNA contamination. Likewise 260/230 also same Phenol contamination and others. The preferable reading should be 2.0-2.2. Are you using NanoDrop!!
Check the following links you get some useful information. If you have patience check my answers link I answered many questions about DNA isolation. Or you can ask. Good Luck!
260/280 and 260/230 Ratios
http://www.nanodrop.com/Library/T009-NanoDrop%201000-&-NanoDrop%208000-Nucleic-Acid-Purity-Ratios.pdf
Assessment of Nucleic Acid Purity
http://www.nanodrop.com/Library/T042-NanoDrop-Spectrophotometers-Nucleic-Acid-Purity-Ratios.pdf
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