The blood samples would be needed for DNA profiling of the incinerated bodies of the victims, to establish the identities.
Earlier today, autopsy of the five bodies which have been recovered so far was conducted, a Defence spokesperson said.
Meanwhile, the victims' families, who have been put up in Mumbai by the Navy, were taken to the docks where the ill-fated submarine was anchored.
Eighteen Navy personnel, including three officers, were on board the Russia-made submarine when a devastating fire ripped through it following serial explosions on Tuesday midnight.