Gene profiling of the early healing rat medial collateral ligament

The objective of the study was to better understand the mechanism behind scar formation by identifying ECM factors and other unique genes differentially expressed during rat ligament healing via microarray. Rat medial collateral ligaments (MCL) were surgically transected or left intact. MCLs were collected at day 3 or 7 post-injury and used for microarray analysis. Results were compared to the normal intact ligaments. A total of 27 rats were used in the study. Animals were randomly placed in 1 of 3 groups (day 3, day 7, intact CX) with nine animals included with each time (9 rats/group). At the time of collection, MCLs from each time were placed into 3 pools (3 MCLs/pool), resulting in 3 reps per time, and usd for microarray analysis. A total of 9 gene chips were used for the experiment (3 chips/day).