We generated $6.9 billion of sales in the first quarter with 30% core revenue growth.
We saw over 20% growth in the developed market, led by North America and Western Europe.
High-growth markets were up more than 45%, largely driven by the recovery in China.
Our gross profit margin increased 580 basis points year-over-year to 62% in the first quarter, largely due to higher sales volumes and the positive impact of higher-margin product mix.
Our operating profit margin of 29.1% was up 1,300 basis points year-over-year, including more than 900 basis points of core margin expansion as a result of higher gross margins and lower operating expenses as we continue to see limited travel and other related costs.
Adjusted diluted net earnings per common share of $2.52 were up 140% versus last year.
We generated $1.6 billion of free cash flow in the quarter, an increase of 135% year-over-year.
Now in the first quarter, we deployed more than $400 million of capital toward mergers and acquisitions across all three segments.
Between these four businesses, we're investing more than $1 billion in 2021 to continue to meet our customers' needs today and well into the future.
Life Sciences reported revenue increased 115% as a result of the Cytiva acquisition, and core revenue was up 41.5%.
In our bioprocessing businesses, accelerating demand for COVID-related vaccines and therapeutic development and production drove a combined core revenue growth rate of more than 60% at Cytiva and Pall Biotech.
Reported revenue was up 34%, and core revenue grew 31%.
Each of our largest operating companies in the platform achieved high single digit or better core revenue growth, led by Cepheid, which achieved more than 90% core revenue growth.
In response to the unprecedented demand for Cepheid's rapid point-of-care molecular test, the team again increased production capacity and shipped over 10 million respiratory test cartridges in the first quarter.
Roughly half of the tests shipped were COVID-only tests, and the other half were 4-in-1 combination test for COVID-19 Flu A, Flu B and RSV.
Reported revenue grew 6.5% and core revenue was up 3.5%.
Additionally, we expect to have operating profit fall-through of approximately 40% in the second quarter and for the remainder of 2021.
For the full year 2021, we now expect to deliver high teens core revenue growth.
This would include an estimated $2 billion of 2021 revenue at Cytiva and Pall Biotech associated with vaccines and therapeutics, which is higher than our previous expectation of $1.3 billion.
And at Cepheid, we'll continue ramping capacity through the year and now expect to ship approximately 45 million tests in 2021 compared to our prior estimate of 36 million tests.

Summary:
We generated $6.9 billion of sales in the first quarter with 30% core revenue growth.
We saw over 20% growth in the developed market, led by North America and Western Europe.
Adjusted diluted net earnings per common share of $2.52 were up 140% versus last year.
For the full year 2021, we now expect to deliver high teens core revenue growth.