portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">工作中發現,有部分檢驗員對培養基的使用存在障礙,借此機會和大家分享討論一下大家常見的對培養基存在的一些疑問。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">1、培養基煮沸溶解后再高壓滅菌,還是直接高壓滅菌存在疑惑。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">拿麥康凱瓊脂舉個例子,溶解后滅菌,平板上沒有不溶的結晶紫,沒有紫色的斑點;相對比未溶解滅菌的,平板上有結晶紫和紫色的斑點。portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; color: rgb(241,136,35); padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">所以正確的做法是先煮沸溶解后再高壓滅菌。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">2、培養基PH值為什么不在標準范圍內?
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; color: rgb(241,136,35); padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">其實出現這個情況的問題有很多種,大致我分為這么6大點:
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">①質量不好(生產廠家出廠時portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">pH就不正確);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">②滅菌問題(高壓滅菌溫度過高或滅菌時間過長,導致葡萄糖類焦化從而portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">pH降低);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">③保存時間(超過保質期或結塊);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">④水質出現問題(可以用去離子水、純化水、蒸餾水不能用礦泉水、自來水);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">⑤保存溫度(保存溫度過高);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">⑥光線直射總結本人認為以上6點都可能導致培養基portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">pH出現偏差,如果出現此類問題,建議逐一排查,直到問題解決。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">3、培養基高壓滅菌時為什么會焦化?
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; color: rgb(241,136,35); padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">不少檢驗人員在實驗時,發現經過滅菌的培養基有焦化現象,我認為引起此現象的主要原因有以下4點:
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">①可能你滅菌的時候溫度超過了121℃(正常115-116℃20min即可);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">②滅菌時間過長;
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">③培養基在容器中裝的太多(不要超過容器容量的80%);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">④滅完菌的培養基在高溫環境中保存的時間過長,這些都會導致培養基發生焦化現象。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">4、培養基PH怎么測定?
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; color: rgb(241,136,35); padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">通常分兩種情況:
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">①對于無需高壓滅菌的培養基,先煮沸溶解后再冷卻至25℃時,測定其portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">pH值(固體培養基至少測2個點,取其平均值);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">②對于需要高壓滅菌的培養基,高壓滅菌后,冷卻至25℃測其pH(固體培養基至少測2個點,取其平均值)。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">5、含瓊脂培養基在倒平板為什么有時候不凝固或凝固不好?
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; color: rgb(241,136,35); padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">針對以上情況,我做了分析:
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">①針對需要高壓滅菌的培養基,倒平板時候要先搖勻(因為瓊脂分子量比較大,在冷卻過程中容易沉淀到底部,導致瓊脂分散不均勻);
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">②針對無需高壓滅菌的培養基,一次煮沸溶解后不能直接倒平板,應重復煮沸溶解3-5次(因為一次不能確保瓊脂完全溶解)。
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">6、為什么同一品牌的不同批號,粉末顏色有差別?
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; color: rgb(241,136,35); padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">portant; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">分析可能有3個原因:
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">①此培養基成分含有染料或指示劑;
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">②不同批次粉末培養基含水量不同,一般要求≤6%,含水量越高,顏色越深;
portant; font-size: 16px; word-wrap: break-word !important; max-width: ; font-family: 宋體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; letter-spacing: 0px; padding-right: 0px">③加工時球磨時間越長顏色越深。
portant; font-size: 12px; word-wrap: break-word !important; max-width: ; font-family: 黑體; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; padding-right: 0px">文章來源食品論壇網友分享,轉載僅為知識分享