Bioanalyser For RNA degradation, contradiction! - (Mar/01/2005 )

By using bioanalyzer 2100 Agilent, I got a strange result. The ratio 28s/18s is 0.9, but seems not so much degradation (basiline is low and not many small peaks between 18s and 28s peak and before 18s peak. The RIN is 8.9 (seems good).

I even used the degradometer to ananlyze the degradation fator, it is no more than 3 (more than 8 means significant degradation happening)

Does anybody know why ratio is so low, but the degradation is not so much? Seems contradiction.

I answer this question to get rid of an urban legend: Maniatis suggested years ago that the 28S/18S ratio is indicative of RNA integrity. No reference for this statement.

The below described RNA is perfectly intact (Degradation factor 3, RIN 8.9). The 28S/18S ratio is dependent on 1) Tissue type 2) Cell division 3) Apoptosis but NOT generally on integrity.

I hope this helps,

Herbert

By using bioanalyzer 2100 Agilent, I got a strange result. The ratio 28s/18s is 0.9, but seems not so much degradation (basiline is low and not many small peaks between 18s and 28s peak and before 18s peak. The RIN is 8.9 (seems good).

I even used the degradometer to ananlyze the degradation fator, it is no more than 3 (more than 8 means significant degradation happening)

Does anybody know why ratio is so low, but the degradation is not so much? Seems contradiction.