Thorén S A, Suurkuusk J, Holma B
Institute of Hygiene, University of Copenhagen, Denmark.
J Biochem Biophys Methods. 1989 Mar;18(2):149-56. doi: 10.1016/0165-022x(89)90076-6.
Monitoring heat flux values below approx. 4 microW requires in microcalorimetry non-standard experimental procedures in order to achieve high accuracy and reproducibility. With 5 ml ampoules, stable baselines are reached in 70 min if a three-level pre-thermostating procedure is used and if the gas phase above the liquid is reduced to 0.5 ml or less. A pairwise procedure of reference/measuring ampoules is used. Autoclaved sealing material of teflon, sterilized stainless steel ampoules in contact with a standard cell medium and culture plates of polystyrene do not contribute to measured heat flux. Further, we found that a standard cell culture medium develops a significant thermal heat flux, 0.10 microW.ml-1, probably reflecting an oxidation process in the medium itself.
监测约4微瓦以下的热通量值，在微量量热法中需要采用非标准实验程序，以实现高精度和可重复性。对于5毫升安瓿，如果使用三级预恒温程序，并且将液体上方的气相减少到0.5毫升或更少，则在70分钟内可达到稳定基线。采用参比/测量安瓿的成对程序。经过高压灭菌的聚四氟乙烯密封材料、与标准细胞培养基接触的经过灭菌的不锈钢安瓿以及聚苯乙烯培养板对测量的热通量没有影响。此外，我们发现标准细胞培养基会产生显著的热通量，为0.10微瓦·毫升-1，这可能反映了培养基自身的氧化过程。
