My son born a month back is suspected to have Down Syndrome. we went for an ECG & found to be normal. Doctor have adviced for Karyotype test. Blood sample has been taken two times by Ranbaxy lab persons, but every time they are telling that something called cell culture is not taking place. what can be problem? Now they are asking for 3rd time Blood sample. it is very pity for taking the blood of 1 month old for the 3rd time as his veins are still not showing up.