不同固定剂及保存时间对微微型浮游生物样品测定的影响

对比了用流式细胞术现场测定及用多聚甲醛、戊二醛及两者的混合物这三种常用固定剂进行固定保存对微微型浮游生物样品的影响。结果表明,在1个月内,细胞数量变化并不显著,但随着保存时间的增加,细胞数量明显减少,且散射光信号明显增大。除原绿球藻的藻红素荧光基本不变、微微型真核浮游植物的藻红素荧光大幅增加外,其余荧光信号均发生不同程度的减少。同时,戊二醛所引起的微微型真核浮游植物荧光信号的极大改变会影响类群的界定。如有可能,应该尽量现场测定微微型浮游生物样品,否则建议采用多聚甲醛或其与戊二醛的混合物作为固定剂,将样品保存于液氮中,待返回实验室后尽快进行测定。

Effects of different fixatives and time of storage on the determination of picoplankton

The effects of three different fixatives (including paraformaldehyde,glutaraldehyde and the mixture of the two) and time of storage on the determination of picoplankton are compared.The results show that there is not the evident variation in cell numbers within a month,while with the increase of the storage time,the great reduce in cell numbers and increase in scatters were found.There are decreases in fluorescence signals except the stablility for Prochlorococcus and increasing abruptly for picoeukaryotes in phycoerythrin fluorescence.Besides,the increase in picoeukaryotic fluorescence signals aroused by glutaraldehyde could affect the discrimination.On-board determination of picoplankton is preferred,if possible.Otherwise,it is better to use paraformaldehyde or the mixture of paraformaldehyde and glutaraldehyde as fixatives,the samples stored in liquid nitrogen should be analyzed as soon as possible.