PerkinElmer (NYSE: PKI) stock skyrocketed 48% in 2020 -- one of its best performances in years. The demand for COVID-19 testing was the primary factor behind that strong growth. Yet PerkinElmer hasn't received a lot of attention from investors seeking to profit from the surge in testing. The healthcare company announced its fourth-quarter results after the market close on Tuesday. Again, COVID-19 was the big story. Here are the highlights from PerkinElmer's Q4 update. Image source: Getty Images. By the numbers PerkinElmer reported revenue in the fourth quarter of $1.4 billion. This reflected a 68% increase from the prior-year period revenue total of $805 million. It also topped the Wall Street consensus estimate of $1.22 billion. How did PerkinElmer's bottom line look in the fourth quarter? The company reported net income of $380.4 million, or $3.38 per share, based on generally accepted accounting principles (GAAP). This was a huge improvement from GAAP earnings of $64.5 million, or $0.58 per share, posted in the same period in 2019. The company's adjusted net income in the fourth quarter came in at $3.96 per share -- nearly triple the adjusted earnings of $1.35 recorded in the prior-year period. This result also trounced the average analyst adjusted earnings estimate of $3.00 per share. Behind the numbers PerkinElmer is organized into two business segments. There were striking differences between how those segments performed in the fourth quarter. The company's diagnostics segment ranked as its biggest moneymaker. The segment generated revenue of $852 million in the fourth quarter, jumping 176% year over year. This huge increase stemmed in large part from higher demand for COVID-19 testing. Q4 revenue for PerkinElmer's discovery and analytical solutions segment totaled $496 million, up only 1% year over year. On an organic basis, the segment's revenue declined by 2% from the prior-year period. The strong overall revenue growth boosted PerkinElmer's earnings. It also helped that there was over $32 million in debt extinguishment costs incurred in the prior-year period compared to none in the fourth quarter of 2020. Looking ahead CEO Prahlad Singh said, "As we look ahead, I could not be more excited about the future for PerkinElmer." That future looks pretty good, which could bode well for the healthcare stock in 2021. PerkinElmer expects that revenue for full-year 2021 will be at least $4.08 billion. The company anticipates GAAP earnings per share (EPS) from continuing operations to be at least $6.73, with adjusted non-GAAP EPS of at least $8.50. Probably the main wild card for the company will be how long demand remains strong for COVID-19 testing. However, with new coronavirus variants potentially extending the duration it will take for the world to reach herd immunity, it seems likely that PerkinElmer investors won't have to be concerned about testing demand falling significantly anytime soon. 10 stocks we like better than PerkinElmerWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and PerkinElmer wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of November 20, 2020 Keith Speights has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source