=====Centrifugation XL-1000=====
  - precaution during centrifugation of barcoded samples.
          * vacuette handled carefully  in centrifuge.
          * Do not rotate vacuette after keeping in centrifuge.
          * Samples must centrifuge for 10  mins.
          * After centrifugation, if clot have not a flat surface again centrifuge for 10 mins.