Table 1.

Diagnostic modalities for targeting sepsis therapies.

Method	Advantage	Challenges
RNA
qPCR	Targeted quantification of key genes, fast, easy interpretation	Limited to a few genes
Microarray	High throughput analysis of larger groups of genes (1000s)	Time consuming assay and data analysis
RNA sequencing	Comprehensive analysis of very large groups of gene transcripts (10,000s)	Time consuming assay and data analysis
Proteins
Lateral flow test	Fast (minutes), simple	Limited to a single protein, not quantifiable
ELISA	Many commercial options for large number of proteins, no interactions between reagents	Time consuming assay
Multiplex platforms	Smaller sample volumes, faster data acquisition vs. ELISA, can simultaneously study proteins from many different pathways	Many platforms, many reagent manufacturers, optimisation of sample dilutions, complex analysis
O-link	High throughput, high sensitivity	Relative concentration values
Lipids & metabolites
Mass spectrometry	Sensitive and specific detection of metabolites	Expensive, time consuming, complex analyses
ELISA	Easy to perform	Single lipids, challenges with sample preparation due to lipid half-lives
Cells
Flow cytometry	Unaltered imaging of cells, ability to study function and phenotype of specific circulating cells	Time consuming, complex protocols and data analysis
Functional responses	Ability to study cell function outside the human body	Time consuming Not standardised (antigens, stimulation duration, read-out)