<prompt> Reverse Cold Chain is used for -Carrying stool samples of polio patiens from a PHC to the labTranspoing outdated vaccines from PHC to district hospitalTranspoing vaccines to lab. to check its potencyTranspoing vaccine form camps to sub - centre  <response>: Ans. is a i.e., Carrying stool samples of polio patients from MC to lab Reverse cold chain is for transpo of ble poliovirus in stool to an investigation centre. 