Tagged Questions
1
vote
1answer
25 views
How can I save bacillus strains on filter paper without an -80 degree freezer?
I want to save my bacillus strains but I don't have access to a -80 degree freezer. What are possible alternatives?
2
votes
1answer
39 views
Does bleach destroy RNAse activity, and if so, how does it do it?
I am working with RNA samples, and I'm trying to be very careful about RNAse contamination.
I have some questions about bleach, though. Some people say that a solution of bleach is enough to destroy ...
5
votes
2answers
49 views
Is wiping with RNAse Zap enough to destroy RNAse activity?
From the RNAseZap MSDS, it is an SDS at some unknown concentration, maybe with some NaOH?
Some other links suggest there is some NaOH as well.
The Ambion site states that RNAseZap destroys RNAse ...
1
vote
1answer
21 views
Amount of reverse transcriptase in µg or mM for qRT-PCR
I am trying to calculate a titration amount for a molecule which I would like to use in my PCR samples. Different molecules have different densities so I would like to calculate the appropriate ...
1
vote
0answers
32 views
Can I heat Trizol?
I wonder if I can heat Trizol reagent for 30 min 65C. The goal is to disrupt protein-RNA complex while inhibiting nucleases. (I can't use RNasin cause it's inactivated in 65C, and can't use RVC cause ...
3
votes
1answer
56 views
205 nm UV-Vis readings
Typically we determine the concentration of proteins using a 280 nm reading. However, it is reasonable to use 205 nm. I was curious about the effectiveness of this method.
2
votes
3answers
82 views
Improving Gel Extraction yields
How can I improve my Gel Extraction yields. We use the standard protocol from Qiagen, gel extraction, dissolve in QG buffer at 42C and purify via anion exchange columns. However, with 500 ng we ...
4
votes
1answer
48 views
What is a simple protocol for staining cells in suspension?
I am an engineering student studying how electric fields affect cells, specifically the phenomena of electroporation in living cells.
I know that electroporation is widely used for introducing genes ...
4
votes
2answers
412 views
What are the advantages and disadvantages of using beta-galactosidase compared to luciferase as a reporter gene?
In the University labs, we have used Beta-galactosidase as a reporter gene to quantify the expression initiated by the stress-response promoter in yeast. This was done by exposing one of the two ...
6
votes
1answer
51 views
Is there a Reverse Transcription optimization for long, 9kb, transcripts?
Has anyone optimized RT for long transcripts (9kb)? The downstream application will be PCR amplification and Illumina library prep. It will be trivial to make internal primers sets for the PCR that ...
15
votes
2answers
390 views
How long can I store extracted RNA?
If I extract RNA from a (leaf tissue) sample using a one-step phenol:chloroform extraction, how long can those samples be stored at -80°C? And how many times can I defrost and refreeze them before ...
8
votes
2answers
824 views
How do I clean and calibrate pipettes, and how often should I do it?
I work in a lab where all the pipettes are shared. We often have visiting students who come and use the pipettes for a short project. So when I work with them, they might have been handled by other ...
8
votes
1answer
3k views
Why do we add salt when precipitating DNA?
All the DNA extraction protocols I have seen involve adding salts to the extraction buffer. What is the purpose of the salts? What happens if they aren't included?
10
votes
2answers
2k views
How do I clean phenol contaminated RNA without losing any of the sample?
I recently extracted RNA from developing plant leaves for the first time, as part of a very long and intensive experiment. The samples were extremely precious because of the amount of effort that went ...
