1.   Northern blotting

The quantity of rna species can be quantified by calculating the quantity of rna through northern blotting which provide size and sequence information regarding the rna molecule.

In this technique a sample of rna is separated by an agarose gel and hybridise to a radioactive rna probe that is corresponding to target sequencer. The radio labeled rna is then identified through an autoradiograph.

2.    Reverse transcriptase-real time quantitative pcr

The other technique for quantification of mrna is rt-qpcr, in this technique reverse transcription creates a dna template from the mrna, this single stranded template is known as cdna. The c dna template is amplified through rt-qpcr in a quantitative step during which fluorescence emitted through labeled hybridization probes or intercalating dyes variates as dna amplification process proceeds. With the standard curve qpcr can create an absolute measurement of the number of copies of real rna.

3.   Hybridisation micro array

This method comprises of single array or chip that include probes to know transcript level for every known gene in the genome therefore assist in quantification of rna species.

4.  Serial analysis of gene expression and rna sequencing are tag based methods which can give a relative measurement of the cellular concentration of diverse rna.