Maxson Michelle E, Cook Emily, Casadevall Arturo, Zaragoza Oscar
Albert Einstein College of Medicine, Department of Microbiology and Immunology, Bronx, NY 10461, USA.
Fungal Genet Biol. 2007 Mar;44(3):180-6. doi: 10.1016/j.fgb.2006.07.010. Epub 2006 Sep 11.
We present a new method to measure capsule size in the human fungal pathogen Cryptococcus neoformans that avoids the limitations and biases inherent in India ink measurements. The method is based on the use of gamma-radiation, which efficiently releases the capsule from the cell. By comparing the volume of irradiated and non-irradiated cells, one can accurately estimate the relative size of the capsule per cell. This method was also used to obtain an estimate of the capsule weight and water content. The C. neoformans capsule is a highly hydrated structure in all the conditions measured. However, after capsule enlargement, the amount of capsular polysaccharide significantly increases, suggesting a that capsule growth has a high energy cost for the cell.
我们提出了一种测量人类真菌病原体新型隐球菌荚膜大小的新方法，该方法避免了印度墨汁测量法固有的局限性和偏差。该方法基于使用伽马辐射，伽马辐射能有效地使荚膜从细胞中释放出来。通过比较经辐射和未经辐射的细胞体积，可以准确估计每个细胞荚膜的相对大小。此方法还用于估算荚膜的重量和含水量。在所测量的所有条件下，新型隐球菌的荚膜都是高度水合的结构。然而，在荚膜增大后，荚膜多糖的量显著增加，这表明荚膜生长对细胞来说具有高昂的能量成本。
