While others simply sided with “defined” as their definition of “serum-free”.
#Serum definition free#
Some agreed on no serum at all as their definition with some conditional variations such as serum-derived components being fair game or no animal source as a restriction.Īnother defined “serum-free” as free of FBS. However, when the same question was asked on the BioInformant LinkedIn page, there was no specific answer that stood out as the clear winner. Poll time! What does the term “serum free” mean to you? Choose an option below or leave your answer in comments: When the question was asked on Twitter the results leaned towards a cell culture media that contains “no animal or human serum.” So what does serum-free mean to you? The Results Are In Does it mean free of FBS? Or does it mean xeno-free – absent of all animal components? Is it defined or chemically defined? One thing was obvious: the definition of serum-free was different across various companies in the cell culture space. The question was brought up after examining current “serum-free” products on the market. If you follow BioInformant you may have seen the poll question in your feed, but if you don’t, the results may be surprising. Was the rest of the scientific community as confused as we were? Does anyone know what “serum-free” means? Cade Hildreth of BioInformant, the world’s largest stem cell industry blog, set out to find the answer. Is it clever marketing or is there a scientific definition to the term? By the end of lunch, the table of cell culture media experts could not come to a consensus on how the term was defined. Definitions of normal ALT values should be adjusted for sex and BMI to reduce artificial heterogeneity in blood donor selection and in hepatitis C clinical studies.What does serum-free mean? The question was brought up during a lunch at the World Stem Cell Summit in January.
Depending on the definition, the prevalence of blood donors with normal ALT varied from 82% to 96%, i.e., a range of 14% that of hepatitis C patients with normal ALT varied from 16% to 27%, i.e., a range of 11% the prevalence of IFN responders varied from 25% to 42%, i.e., a range of 17%. BMI and male sex were independently associated (P 23 (D7). The seven definitions (D) of ULN were: D1: 95th percentile of ALT D2: 95th percentile after separating males and females D3: males and females separately, ULN=10 (mean of log10 ALT + 1.96 SD) D4: ULN=45 IU/L given by the manufacturer D5: mean + 1 SD after exclusion of the 5% extreme values D6: 95th percentile after separating subjects with body mass index (BMI) under or equal to the median (23) and D7: 95th percentile after separating subjects according to BMI and sex.
ALT measurements were performed in the same laboratory using the same technique 1,033 donors were prospectively investigated, 186 patients with hepatitis C never treated and 40 patients treated with 3 MU three times per week of IFN-alpha for at least 6 months.
Our aim was to assess factors associated with serum ALT activity in apparently healthy subjects and then to apply seven different definitions of ULN in three different populations so as to assess the prevalence of subjects with normal ALT among blood donors and among hepatitis C patients before (normal ALT hepatitis C patients) and after treatment (interferon responders). However, such a definition can vary and may have practical consequences. In clinical research, the definition of the upper limit of normal (ULN) alanine transaminase (ALT) is never detailed.