The vast majority of work (76%) was done using outbred Sprague-Dawley or Wistar rats. Inbred strains were used on only 12% of occasions. Of the inbred strains, the most widely used was F344 (32.1%), followed by LEW (22.5%). Mutants (=transgenic) were used only in 1% of the studies, reflecting the circumstances explained below. | The vast majority of work (76%) was done using outbred Sprague-Dawley or Wistar rats. Inbred strains were used on only 12% of occasions. Of the inbred strains, the most widely used was F344 (32.1%), followed by LEW (22.5%). Mutants (=transgenic) were used only in 1% of the studies, reflecting the circumstances explained below. |