Abstract: The present disclosure relates to alternative methods of conducting standard blood chemistry tests, the methods typically comprising: extracting an RNA from a blood sample, determining a mRNA level of a predictive gene in the blood sample, and converting the mRNA level of the predictive gene into the blood test result of the target blood component. The present disclosure also relates to blood test for performing the proxy methods. The blood test includes a plasmid with at least an exon of a predictive gene, a reagent for detecting a mRNA level of the predictive gene, and a reagent for detecting a mRNA level of a housekeeping gene.