Essential 10

1. Study Design The experimental unit (e.g. a single animal, litter, or cage of animals). examples

For each experiment, provide brief details of study design including:

1a The groups being compared, including control groups. If no control group has been used, the rationale should be stated.
1b The experimental unit (e.g. a single animal, litter, or cage of animals).
Explanation
Examples

Example 1

 “The present study used the tissues collected at E15.5 from dams fed the 1X choline and 4X choline diets (n = 3 dams per group, per fetal sex; total n = 12 dams). To ensure statistical independence, only one placenta (either male or female) from each dam was used for each experiment. Each placenta, therefore, was considered to be an experimental unit.” [1] 

Example 2

“We have used data collected from high-throughput phenotyping, which is based on a pipeline concept where a mouse is characterized by a series of standardized and validated tests underpinned by standard operating procedures (SOPs)…The individual mouse was considered the experimental unit within the studies.” [2] 

Example 3

“Fish were divided in two groups according to weight (0.7-1.2 g and 1.3-1.7 g) and randomly stocked (at a density of 15 fish per experimental unit) in 24 plastic tanks holding 60 L of water.” [3] 

Example 4

“In the study, n refers to number of animals, with five acquisitions from each [corticostriatal] slice, with a maximum of three slices obtained from each experimental animal used for each protocol (six animals each group).” [4]

  1. Kwan S, King J, Grenier J, Yan J, Jiang X, Roberson M and Caudill M (2018). Maternal Choline Supplementation during Normal Murine Pregnancy Alters the Placental Epigenome: Results of an Exploratory Study. Nutrients. doi: 10.3390/nu10040417
  2. 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
  3. Ribeiro FdAS, Vasquez LA, Fernandes JBK and Sakomura NK (2012). Feeding level and frequency for freshwater angelfish. Revista Brasileira de Zootecnia. doi: 10.1590/S1516-35982012000600033 
  4. Grasselli G, Rossi S, Musella A, Gentile A, Loizzo S, Muzio L, Di Sanza C, Errico F, Musumeci G, Haji N, Fresegna D, Sepman H, De Chiara V, Furlan R, Martino G, Usiello A, Mandolesi G and Centonze D (2013). Abnormal NMDA receptor function exacerbates experimental autoimmune encephalomyelitis. Br J Pharmacol. doi: 10.1111/j.1476-5381.2012.02178.x