ERROR ADMITTED IN CHKLIST USE AND NOT OBTAINING PDC PRIOR TO DEP.

Narrative

ON THE FIFTH AND LAST LEG OF A 12 HR DUTY DAY; FLT DEPARTED THE GATE AT PM57 WITHOUT A PDC. WHEN THE BEFORE START CHKLIST WAS READ; WE HAD NOT RECEIVED THE PDC. WHEN THE ITEMS PERTAINING TO THE DEP CLRNC; RADIOS; XPONDER; TCASII/ACARS; WERE READ; I RESPONDED 'TO GO' AND WE CONTINUED WITH THE BEFORE START CHKLIST TO THE END. 4 0'S WERE IN THE XPONDER AS A REMINDER THAT WE STILL DID NOT HAVE THE PDC. I USUALLY WILL ALSO PLACE THE CHKLIST BTWN THE THROTTLES AS AN ADDITIONAL REMINDER; BUT FAILED TO DO SO THIS TIME. WHEN THE AWABS; FUEL SLIP; AND FINAL WX WERE RECEIVED JUST PRIOR TO PUSHBACK; THE NUMBERS WERE ENTERED; THE SPD BUGS WERE SET AND THE 'AFTER PAPERWORK' ITEMS OF THE CHKLIST WERE READ TO COMPETE THE CHKLIST. USUALLY AT THIS TIME THE PDC OR CLRNC HAS BEEN RECEIVED. AT THIS POINT WE CONTINUED OUR NORMAL HABIT PATTERN; FORGETTING THAT WE STILL DID NOT HAVE THE PDC. WE REALIZED WHAT HAD HAPPENED WHEN DEP CTL TOLD US TO SET THE SQUAWK WHICH WAS STILL ALL 0'S. AFTER REVIEW OF OUR PLTS' OPERATING MANUAL (POM); CONTINUING THE CHKLIST BEYOND AN UNCOMPLETED ITEM IS ACCEPTABLE IN FLT BUT NOT ON THE GND. FOLLOWING THE POM AS IT IS WRITTEN WOULD HAVE PREVENTED THIS SIT.