The Filipino father-of-two was first arrested in January 2012
Nurse Victorino Chua, found guilty of murdering and poisoning patients at Stepping Hill Hospital, has been jailed for a minimum of 35 years.
Chua killed Tracey Arden, 44, and Derek Weaver, 83, at the hospital in Stockport by injecting insulin into saline bags and ampoules.
The father-of-two was convicted on Monday following a three-month trial.
Judge Mr Justice Openshaw described Chua as an "experienced nurse who used cunning" to poison patients.
He was found guilty of tampering with saline bags and ampoules while working on two acute wards at the hospital in Greater Manchester, in June and July 2011.
These were unwittingly used by other nurses, causing a series of insulin overdoses to mainly elderly victims.
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Relatives of Derek Weaver described Chua as 'evil' and said they were 'delighted' with the verdict
Detectives described Chua as a narcissistic psychopath.
His victims' families were at Manchester Crown Court as Chua was told he would serve at least 35 years in prison before being considered for parole.
Speaking outside court after the verdict, Mr Weaver's sister, Lynda Bleasdale, said: "My sister had a heart attack the day before Derek died. Seeing all the stress of it was obviously a contributory factor to that."
She said Chua "obviously enjoyed watching people suffer".
Gary Arden, whose sister Tracey was murdered by Chua, said he felt "surprisingly nothing" for his sister's killer.
He added: "He's been sentenced and the important thing is he's not able to do this to anybody else."
Tracey Arden and Derek Weaver
Chua was found guilty of murdering Tracey Arden and Derek Weaver
Judge Openshaw said it was "strikingly sinister and truly wicked" that Chua did not personally administer the insulin to most of the patients, so it was left to chance which of them were poisoned.
He said Chua poisoned Jack Beeley, 72, to "shut up a patient who he found particularly troublesome".
Grant Misell, 41, was left brain damaged after being poisoned, as the insulin overdose starved his brain of oxygen.
Chua was found not guilty of the murder of 71-year-old Arnold Lancaster but convicted of poisoning him in an act the judge described as "indescribably wicked".
In all, Chua was convicted of two murders, 22 counts of attempted grievous bodily harm, one count of grievous bodily harm, seven attempts of administering poison and one count of administering poison.
He received 25 life sentences in total and showed no emotion as he was taken down to the cells. Judge Openshaw said he would be 84 years old before he was eligible for parole.
Chua's letter
A handwritten letter, described as the "bitter nurse confession", was found in Chua's kitchen
Among the evidence produced by the prosecution was a self-penned letter found at Chua's home, in Stockport, after his arrest in January 2012 for changing prescription charts so patients would get dangerously incorrect amounts of drugs.
In the letter, described as "the bitter nurse confession" by Chua, he said he was "an angel turned into an evil person" and "there's a devil in me". He also wrote of having things he would "take to the grave".
Det Supt Simon Barraclough, who led the investigation for Greater Manchester Police, said Chua failed to show "any form of remorse" throughout the investigation and trial.
Even when being sentenced "there was not a flicker of emotion on his face, apart from what appeared to be just a general contempt for all the proceedings", he added.
'Great distress'
Investigations by police found inconsistencies in Chua's medical qualifications, which they raised with the Department of Health and the Home Office, as well as contacting the Nursing and Midwifery Council (NMC).
Concerns were also raised by a BBC investigation which revealed that fake nursing degrees were being sold in the Philippines for £20.
Nazir Afzal, who was responsible for prosecuting Chua, said the Stepping Hill case raised the "extremely worrying" prospect that many untrained foreign workers could be working in UK hospitals.
However, the NMC said a review of nurses who trained outside the European economic area - including 11,500 Filipino records - found just four with fraudulent qualifications in the last 10 years.
Chief executive Jackie Smith, said: "We checked every single record - I think that was a proportionate response to this one-off but very tragic and very serious event."
She said not all the records of other overseas countries had been checked, adding: "We took advice on what would be a sample of a review across the register that would give us confidence.
"There is no such thing as a fool-proof system - we are not a fraud agency - but do we have a system in place that doesn't just rely on documentation."
In a statement, Stockport NHS Foundation Trust said: "Our thoughts have been with the victims and their families throughout this time.
"We know they have suffered great distress but hope this sentence helps provide some closure for them in terms of seeing that justice has been served."