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Anonymous
Anonymous asked in 科學化學 · 1 decade ago

測定生菌數問題~~~

請問稀釋100倍後,取50ul下去plate劃~

假設結果出來為30個點,那正確的生菌數為多少?包含單位!

Update:

10^-2*50*10^-3=1*1:X==>X=6*10^4CFU/ml

等號前面是不是少寫了:30 ???

最後這樣的答案大大確定對的齁?因為是要上台報告的~"~

而且評審老師剛好是做細菌研究的,怕報錯就糗了!

1 Answer

Rating
  • sidney
    Lv 5
    1 decade ago
    Favorite Answer

    假設取1ml的原菌液,加入9ml的稀釋液,votex一下,混合均勻,形成A液;

    再用滴管,取1ml的A液,再加入另一管同樣9ml的稀釋液,同樣votex一下,形成B液,

    然後用pipet吸取50ul的B液,滴在約45度西的液體agar中充分混合,

    再倒入petri dish中等凝固後 ,出現三十個點,表示在50ul裡活菌,有

    30個colonies,

    算式==>50*10-6:30=1:X==>X=6*105CFU(colony forming unit)/ml,

    此方法為pour plate,常用來鑑別特殊的菌種(用特殊agar培養基),不

    過此法容易殺死sensetive cells...

    2008-10-09 02:42:24 補充:

    更正:50*10^-3:30=1:X==>X=6*10^2CFU/ml

    2008-10-09 02:55:39 補充:

    不好意思,忘了考慮濃度><",

    10^-2*50*10^-3=1*1:X==>X=6*10^4CFU/ml

    2008-10-10 20:11:37 補充:

    對 ,你真是敏銳, 我少寫:30,

    你不要懷疑,大大一出手,便知有沒有^^

    2008-10-12 02:06:05 補充:

    請勿棄置問題,謝謝~

    Source(s): 我的原文微生物課本, 答案更正, 抱歉^^",再更正一次, me
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