Essential 10

4. Randomisation State whether randomisation was used to allocate experimental units to control and treatment groups. If done, provide the method used to generate the randomisation sequence. examples

4a State whether randomisation was used to allocate experimental units to control and treatment groups. If done, provide the method used to generate the randomisation sequence.
4b Describe the strategy used to minimise potential confounders such as the order of treatments and measurements, or animal/cage location. If confounders were not controlled, state this explicitly.
Explanation
Examples

Example 1

“Fifty 12-week-old male Sprague-Dawley rats, weighing 320–360g, were obtained from Guangdong Medical Laboratory Animal Center (Guangzhou, China) and randomly divided into two groups (25 rats/group): the intact group and the castration group. Random numbers were generated using the standard = RAND() function in Microsoft Excel.” [1]    

Example 2

“Animals were randomized after surviving the initial I/R, using a computer based random order generator.” [2] 

Example 3

“At each institute, phenotyping data from both sexes is collected at regular intervals on age-matched wildtype mice of equivalent genetic backgrounds. Cohorts of at least seven homozygote mice of each sex per pipeline were generated…The random allocation of mice to experimental group (wildtype versus knockout) was driven by Mendelian Inheritance.” [3] 

  1. Zhao S, Kang R, Deng T, Luo L, Wang J, Li E, Luo J, Liu L, Wan S and Zhao Z (2018). Comparison of two cannulation methods for assessment of intracavernosal pressure in a rat model. PLoS One. doi: 10.1371/journal.pone.0193543
  2. Jansen of Lorkeers SJ, Gho JMIH, Koudstaal S, van Hout GPJ, Zwetsloot PPM, van Oorschot JWM, van Eeuwijk ECM, Leiner T, Hoefer IE, Goumans M-J, Doevendans PA, Sluijter JPG and Chamuleau SAJ (2015). Xenotransplantation of Human Cardiomyocyte Progenitor Cells Does Not Improve Cardiac Function in a Porcine Model of Chronic Ischemic Heart Failure. Results from a Randomized, Blinded, Placebo Controlled Trial. PLOS ONE. doi: 10.1371/journal.pone.0143953
  3. Karp NA, Mason J, Beaudet AL, Benjamini Y, Bower L, Braun RE, Brown SDM, Chesler EJ, Dickinson ME, Flenniken AM, Fuchs H, Angelis MHd, Gao X, Guo S, Greenaway S, Heller R, Herault Y, Justice MJ, Kurbatova N, Lelliott CJ, Lloyd KCK, Mallon A-M, Mank JE, Masuya H, McKerlie C, Meehan TF, Mott RF, Murray SA, Parkinson H, Ramirez-Solis R, et al. (2017). Prevalence of sexual dimorphism in mammalian phenotypic traits. Nature communications. doi: 10.1038/ncomms15475