Question Detail
What are the reasons for smearing when running mouse tail DNA on an agarose gel?
Medical Devices
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All Answers4
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NinaBuffer4823
2026-09-23
marker也不清晰，基本可以先把DNA降解这个选项放一边，重点查胶和缓冲液体系。0.8%胶可能没煮透，尤其是琼脂糖粉在微波炉加热时看着透明，底部仍有未溶解微球。建议加热到完全沸腾后摇匀，再补少量水至原体积，冷却到60℃左右倒胶。TAE新配后要调pH到8.2-8.4，缓冲液配错浓度或用过多次也会让marker和样品一起拖尾。
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张倩
2026-09-12
动物组织大片段DNA用0.8%胶，普通低电渗琼脂糖足够，不一定要低熔点。选型重点看溶解后是否澄清、批间稳定性。国产里莫纳、赛维尔等常规型跑基因组DNA都可以，先拿lambda DNA或HindIII marker试胶。如果换了两三个批次仍拖尾，瓶颈很可能在提取或电泳条件，不是琼脂糖本身。
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David3430
2026-09-23
十几孔如果电泳槽缓冲液太少、电压太高，发热会让胶局部变软，条带就会模糊。跑大片段基因组DNA建议4-5V/cm，别追时间。TAE液面要没过胶面至少3-5mm，电极不要接反。上样缓冲液含SDS或盐浓度高的，也可能引起拖尾，可以换新鲜6× loading buffer，上样前短离心混匀。
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CindyResearch9032
2026-09-10
鼠尾基因组DNA本身分子量大，容易带蛋白、RNA或高盐。如果上样量偏大，或提取时没充分晾干乙醇，点样孔附近会堆积、整条泳道发糊。建议取2-3μL稀释后测浓度，控制基因组上样量在100-200ng左右，必要时加RNase，提取后用70%乙醇洗两次，溶解在TE里。这样往往能改善拖尾。
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