Hepatitis B virus and microRNAs: Complex interactions affecting hepatitis B virus replication and hepatitis B virus-associated diseases

Table 2 Methods for studying microRNA expression levels

Strategy	Advantages	Disadvantages
qRT-PCR	Can determine absolute miRNA-expression level when compared to standard curve, requires minimal bioinformatics analysis	Analysis of single miRNA at a time; often used to determine expression of small numbers of miRNAs; requires prior identification of miRNAs of interest
miRNA microarray	Can be used to determine expression changes for a large group of miRNAs	Data are expressed as fold change relative to a baseline and not absolute expression values; can require prior identification of miRNAs of interest
Next-generation sequencing	Identifies the complete miRNome and determines absolute expression values in the context of all other cellular miRNAs	Expensive and requires extensive bioinformatics analysis

miRNA: microRNA; qRT-PCR: Quantitative reverse transcription polymerase chain reaction.