Fig. 1

Microsampling protocol design and reproducibility. a In terminal blood sampling, at each time point, groups of mice are exsanguinated to obtain 0.5–0.6 mL blood volumes, which are then subject to leukocyte depletion and saponin lysis before TRIzol treatment. Thus, the number of mice increases proportionally with the number of biological replicates and time points in the study design (number of mice per timepoint X number of timepoints; NT). Microsampling involves obtaining sample volumes as low as 20 μL from the same mouse at different time points, thus confining the number of mice to just biological replicates (N) and significantly lowering costs and biological variability. Leukocyte depletion and saponin lysis are also not performed on the low volume samples, thus saving time and manpower. b Heatmap shows pair-wise Pearson correlation coefficients and the inset shows multidimensional scaling to visualize the level of similarity between the P. vinckei microsamples. Microsamples show low degree of variability and are highly reproducible as proved by tight correlations between biological replicates. c High Pearson correlations were observed between normalized gene expression values (shown as logarithm of fragments per kilobase of transcript per million mapped reads) from microsampling (x-axis) and terminal blood sampling (y-axis) methods. d Bioanalyser electrophoregrams of total RNA from Plasmodium vinckei vinckei CY microsamples show that high quality RNA could be extracted consistently from 20 μL microsamples