April 21 (Reuters) - Life sciences firm Danaher DHR.N topped first-quarter profit expectations on Tuesday, fueled by strong demand for its bioprocessing tools used in drug manufacturing, lifting shares 2% in premarket trading.

The results point to improving market conditions for life sciences companies as pharmaceutical companies ramp up spending on drug discovery and development.

The Washington, D.C.-based company, which makes tools and technologies used by pharmaceutical companies to develop and manufacture drugs, reported adjusted earnings of $2.06 per share for the quarter ended March 27, topping analysts' average estimate of $1.94, according to LSEG data.

CEO Rainer Blair said the company's steady recovery was driven by strength in its bioprocessing unit and better-than-expected performance in the life sciences segment, despite a weaker seasonal demand for respiratory tests.

Total quarterly revenue came in at $5.95 billion, slightly below Wall Street's estimates of $6 billion.

Danaher's biotechnology unit, which includes the Cytiva bioprocessing business that provides equipment and materials to drugmakers, was the standout performer, with core sales - excluding currency fluctuations - up 7% for the quarter.

Core sales in Danaher's life sciences segment, which supplies lab equipment for drug discovery, rose 0.5% in the period, while sales in its diagnostics unit, which makes COVID-19 and other medical testing kits, fell 4%.

"This was a good print from DHR," said Evercore ISI analyst Vijay Kumar.

Danaher slightly raised its full-year adjusted earnings forecast to $8.35 to $8.55 per share, from $8.35 to $8.50 per share previously. Analysts had, on average, expected $8.40 per share.

The company was also upbeat about its $9.9 billion acquisition of Masimo Corporation, announced in February. Blair said Danaher sees "clear opportunities" to enhance Masimo's performance through its business systems and global scale.