Loading ...
Loading ...
Loading ...
76
RNeasy Mini Handbook 10/2019
Appendix B: Storage, Quantification, and
Determination of Quality of RNA
Storage of RNA
Purified RNA may be stored at −30 to −15°C or −90 to −65°C in RNAse-free water. Under
these conditions, no degradation of RNA is detectable after 1 year.
Quantification of RNA
The concentration of RNA should be determined by measuring the absorbance at 260 nm
(
A
260
) in a spectrophotometer (see “Spectrophotometric quantification of RNA” below). For
small amounts of RNA, however, it may be difficult to determine amounts photometrically.
Small amounts of RNA can be accurately quantified using an Agilent
®
2100 bioanalyzer,
quantitative RT-PCR, or fluorometric quantification.
Spectrophotometric quantification of RNA
To ensure significance,
A
260
readings should be greater than 0.15. An absorbance of 1 unit
at 260 nm corresponds to 44 µg of RNA per ml (
A
260
=1 → 44 µg/ml). This relation is valid
only for measurements at a neutral pH. Therefore, if it is necessary to dilute the RNA sample,
this should be done in a buffer with neutral pH.* As discussed below (see “Purity of RNA”,
page 77), the ratio between the absorbance values at 260 and 280 nm gives an estimate of
RNA purity.
* When working with chemicals, always wear a suitable lab coat, disposable gloves, and protective goggles. For
more information, consult the appropriate safety data sheets (SDSs), available from the product supplier.
Loading ...
Loading ...
Loading ...