Fetal bovine serum specific cell type. When changing from batch to batch it is usual to adapt the cells to the new batch of material, for example, by mixing 50% of the old serum with 50% of the new serum and allowing the cells to acclimatise to the new material. Serum is stored frozen to preserve the stability of components such as growth factors. When serum is thawed, some precipitation may be seen. This is a normal phenomenon and it does not compromise the quality of serum in any way. The precipitate may be removed by transferring the serum to sterile tubes and
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