“…Although these techniques are relatively labor-intensive and time-consuming, they are considered the gold-standard techniques for these measurements at the present time. Many of these techniques have been developed or refined in John Bertram's laboratory (Bertram, 2001;Cullen-McEwen, Armitage, Nyengaard, & Bertram, 2012;Cullen-McEwen, Douglas-Denton, & Bertram, 2012;Puelles et al, 2014;Puelles et al, 2016) and are routinely used in our laboratory (often in collaboration with researchers from the Bertram lab) (Gubhaju et al, 2009;Maka et al, 2008;Mitchell, Louey, Cock, Harding, & Black, 2004;Ryan et al, 2018;Ryan, Atik, De Matteo, Harding, & Black, 2013;Sutherland et al, 2013;Sutherland, Ryan, Dahl, Albertine, & Black, 2016). In this article, we describe in "step-by-step" detail a number of these stereological techniques (including details on how to apply these techniques in the assessment of kidneys of differing sizes and levels of maturity), with the aim that these methodologies will be a valuable resource to other researchers in the field.…”