Is total RNA extraction possible from small volume goat milk (7.5 mL) for RT-qPCR studies?

This study aimed to study the application availability of RT-qPCR by total RNA extraction from small volumes of milk samples. RNA was extracted from 7,5 mL milk. Amount and quality of RNA and Ct results obtained via RT-qPCR were compared with the values obtained from 100 mL milk. A(260)/A(280) ratio of absorbance was found to be higher than 1,70 in all samples. Mean RNA purity were identified as 1,87 +/- 0,07 and 1,77 +/- 0,01 in 7,5 mL and 100 mL milk samples respectively. While mean total RNA concentration was 149,37 +/- 43,40 mu g/mL in 7,5 mL milk sample, it was measured to be 309,03 +/- 77,82 mu g/mL in 100 mL milk sample. Mean somatic cell count (SCC) of the 8 goats used in the study was calculated as 486,37 +/- 185,68 x 10(3) cells/mL. Ribosomal Protein Lateral Stalk Subunit P0 (RPLP0) gene which is accepted as the reference gene in goat somatic cells was used to test application availability of obtained RNA in RT-qPCR. Mean Ct results were found to be 20,33 +/- 0,39 and 19,51 +/- 0,41 in 7,5 mL and 100 mL groups respectively, creating no difference between the two groups (P = 0,170). Quality and amount of obtained RNA and Ct results showed that it was possible to extract RNA by using 7,5 mL milk.