Fetal bovine serum and virus, endotoxin, haemoglobin, IgG and total protein assays. Ethical questions have been raised regarding the blood collection process due to the potential suffering caused to the fetus. Although anoxia or active slaughter could be used to induce unconsciousness or death prior to serum harvesting, exposure of live unborn calves to oxygen can cause them to gain awareness before being killed, resulting in active debate about the ethics of harvesting serum. Fetal bovine serum is commercially available from many manufacturers, and because cells grown in vitro are highly sensitive, customers usually test specific batches to check for suitability for their
Blood, Sweat & Tears 4 Blood, Sweat & Tears 4 Blood, Sweat & Tears 4 is the fourth album by the band Blood, Sweat & Tears, released in 1971. It peaked at number 10 on the Billboard Pop albums chart. The band invited former member Al Kooper to contribute the song "John the Baptist (Holy John)." Trombonist Dave Bargeron replaced Jerry Hyman. David Clayton-Thomas left as lead vocalist to pursue a solo career after the release of "BS&T 4", as did founding members Dick Halligan and Fred Lipsius. Clayton-Thomas would return to the lineup for "New City". Writing for Allmusic, critic William Ruhlman wrote "the