Hi all, I'm the inventory guy for a lab, and for various reasons the techs really prefer test tube racks with thicker epoxy coating. Anyone know a supplier that still makes those? What's tricky is that the thicker coating used to be the norm, so a lot of sites have pics that show the thicker coating but actually ship the thinner.

For an illustration of what I mean, check the two photos at https://www.fishersci.com/shop/products/bel-art-scienceware-poxygrid-wire-test-tube-racks-18-20mm-4/14793233 - the first one shows the thicker resin, the second one the thinner stuff that they actually send out.

Hi everyone, hope you're having a lovely weekend! Never posted here before, I know the title sounds kind of dramatic, but I don't know where else I'd be able to get some insight on this from people in the industry...

I am a recent biochem graduate, and I work at a company that describes themselves as "a manufacturer of reagents and tools for the life sciences". When I started working there I'd assumed that we would be making products and reagents to sell to academic customers. Turns out we don't manufacture (or even test!!) a single product, we import from China, re-label them with our company's logo and sell them on with a very large profit margin. We're apparently allowed to call ourselves the manufacturers because we change the labels on the products. In the food industry, for example, you have to be totally transparent about where you source things from. However in the life sciences industry, you don't.

People can Google these labs and buy from them directly. I can't see many benefits of buying from us instead of these labs apart from:

1. Not having to deal with customs and import. However if you really didn't want to do this then you could just order from a distributor company. The fact that we are relabelling products and stretching the truth about who manufactures these products makes us different from a "normal" distributor who would be transparent about the company that they are supplying from, and take a smaller profit margin for the service of dealing with the customs and import.
2. Slightly better customer service. However if a customer has issues with the product, we have to discuss it with the Chinese labs anyway, and our response time to the customer depends on their response time to us. We don't even know basic details about the products - if someone asks something like the sequence of a protein we have to ask the lab, and there is a delay in the response time to the customer because of the time zone difference.
3. Maybe customers just don't know about these labs??
4. Maybe people feel like buying from China is riskier/lower quality than buying from the place where I work. However this is the worst reason because in this case the customer doesn't know they are buying from China anyway.

Is the whole industry like this? It weighs on my conscience, I feel like I'm scamming customers every day. From my perspective, based on what I know now, the money that labs spend on our products is money from governments, research institutions and charities that could have been spent more efficiently elsewhere, and therefore allowed research to progress faster. I know they have a choice from where they buy, but how can they make an informed decision if the whole industry is set up so that they don't have the right information to?

I'm very new to this, maybe I'm just overreacting or don't see the whole picture, so I just wanted to ask -

1. Are there any more benefits of the company that I haven't listed? I want to gain a rounded perspective on this.
2. Are most life sciences suppliers like this, or is it just the place that I work?
3. I feel like there has to be a better way of connecting research labs with the actual manufacturers of products. What are your suggestions?

Thank you so much for reading this. Please do not name any companies by name in the comments, but I would really appreciate some insight from someone who actually knows how the life sciences industry works.

Every year I try to get my hands on one of these sweatshirts from the thermo promotion and today I was successful!!! So pumped. Look at how cute the snowman is with his little DNA arms 😭

Hi everyone,

I just started as a Master's student in a big lab. I am being mentored by a senior PhD student and I recently had a problem where I'm not sure how to best resolve it...

A couple of days ago, I was running a long experiment that required a biosafety hood for essentially the whole day. I was harvesting tumors and converting them into cell lines. With the given protocol, I would need the hood for 5+ hours. One of my other lab members confronted me about it and told me that I should not reserve the hood for that much time because it leaves them with one less hood to work with. The thing is...my mentor has done this many times and no one has said anything about this. He just taught me this protocol and this was my first time doing it on my own (he's presently away for a conference). I don't do this experiment often. I reserved the hood the night before because timeslots go fast and everyone books their reservation in the morning. During the confrontation, they said that I should've been more considerate of others and only reserve for specific times I needed it - I think this point came from the fact that the harvesting part took a bit of time because the tumors inside of mice was more complex than expected. Because of this, I didn't start using the hood until 1.5 hours after the start time of my booking. But I still used it for the rest of the duration that I booked it for.

My question is: what would you do? I'm still fairly new to the protocol and I'm not sure where I can split times and things. Once the harvest is over, I need to go to the hood immediately otherwise I lose a lot of viable cells. What if, by the time I'm done the harvest and then I go to book a hood, there are no hoods available? My colleague said I can just ask someone to spare me their hood time - but last time I did that, no one was willing to let me borrow their hood. At the time of the confrontation, when they started raising their voice, it attracted many of the other lab members and everyone stood on their side and agreed with them. I felt very ganged up and because I was running on a tight time schedule and they confronted me during the experiment, I didn't react well (just very flustered and wanted to continue with my experiment but they kept yelling my name to get me to stop and listen to them). Ever since that confrontation, the lab has felt awkward and I feel alienated. I don't know what to do...I have another batch of mice with the genotypes that I need to be harvested next week and I'm not sure how I should go about the hood situation.

I'd appreciate any advice for this. Thanks (sorry for the long post)

I was hired as a research technician in a university lab (college of medicine) a couple months ago and I’m wondering if the duties expected of me are on par with other people in the same position. I’m not complaining, necessarily, it just seems as though what’s expected of me is different from techs in other labs (and my previous experience). My job has three parts: 1) maintaining a colony of 600+ mice (breedings, genotyping, euthanizing, weaning, med reports, maintaining the database) 2) bench work (qPCR, micro dissection, RNA extraction, behavioral experiments, etc.) 3) lab management (literally everything - orders, waste disposal, EHS compliance, cleaning, re-stocking, autoclaving…I drew the line when told I was responsible for washing all dishes/instruments). I’m not allowed overtime, so I have to cram everything into 40 hours a week. I’m extremely meticulous, so it does take me a little longer than some people to do the same tasks, but I work hard and I don’t make mistakes. My PI is genuinely wonderful and very understanding. If I say I’m struggling, they accommodate me. But I HATE doing that, because it feels like I’m letting everyone down. Especially since the message I get is that all my predecessors managed what I’m doing and more without complaint. So. Other techs- do you do more, less, the same? PIs/grad students - is this what you’d expect from a tech in your lab? I have 10 years of experience in labs, but my previous department was a different world compared to medicine, so I’m not sure what’s reasonable.

I am on the taller side.. How do you prevent neck pain when bench work all day standing up?

My neck is literally in so much pain by mid day

hi all! in my lab we have had cell contamination for weeks and we can’t seem to figure out the source. We usually know when we have a contamination due to changes in cell media color, pH and turbidity. However, this seems like a hidden contamination that we saw when we looked at the cells in the confocal microscope. We have been calling them highly motile structures inside the cell. Yes, inside because we don’t see them floating around in the media and when we do a mycoplasma it comes negative.

Does anyone have an idea of what it could be?

These are COS7 cells with Hoechst stain (10uM). 63x magnification.

Hi,
this may be quite specific but I started working with the Thermo Scientific GeneJet Gel Extraction Kit a month ago. I would appreciate your tips and tricks on how to increase the DNA yield. I just want to optimise the process faster so I don't have to cry myself to sleep lol. Thanks!!

I interviewed last week for a postdoc in the UK and thought it went well. I followed up a few days ago as I hadn’t heard back in a week, HR told me the panel was still making their decision.

Later that night the PI on the project (and head of the panel) emails to check if I’m still interested and after confirming I am asks if i can meet this coming Monday for a follow up chat.

Does anyone have any experience of this while applying for postdocs in the UK and have any suggestions for what kinds of questions they might ask? First interview focused on my experience for the position etc but not many technical questions on the project so should I be prepped for those and stuff like vision for the project? Any help appreciated 😊

Hello! I'm currently a 4th year PhD and just got notified I would be awarded an F31 for 3 years worth of funding. This is, my department avg graduation time is about 5.5 years, and I would hope to graduate around that mark. Is this funding that can follow me to a postdoc or would I have to give it up to graduate? Is it possible this will encourage my PI to delay my graduation?

From where should I repeat the extraction, from the bromocresol green or from the chloroform?

"A certain amount of the test solution was accurately pipetted and evaporated, and the residue was dissolved in 3 mL of phosphate buffer solution of pH 4.5. The solution was transferred into a separatory funnel and was thoroughly mixed with 3 ml. of bromocresol green solution (0.03%). Thirty minutes later, 5 ml. of chloroform was added into it and shaken for 2 min. The lower layer was separated after 10 min. The extraction was continued for three times, and the extracts were mixed in a volumetric flask."

I have this reference ⬆️. Thanks.

Was looking at a paper recently and found this peculiar looking graph. The row of data points at exactly 200 (and also a few at exactly 300 and possibly 150) seem a bit odd. The data is for input resistance in ephys recordings

Some context for you rats: I’m finally finishing up writing a manuscript that is largely based on the work I did as a master student (currently 2nd year PhD). I would say half of the data is from my masters, the other half I did during my first two years as a phd student. Now bc I was a wee masters student who was just starting out in the lab, our post-doc (the other co-author) did the experiments for the first half of data, but I analyzed and made the figures. The second half of this manuscript is all me.

Now for the writing, the first draft was probably 70/30 with him contributing some to the introduction and discussion. Since that draft, however, much of what he wrote has been scrapped by our PI and I’ve been the one editing, writing, and doing the final push. I gave him a chance to contribute to the discussion this past week and all he did was rewrite a sentence into a more convoluted form (that I ended up rewriting) and highlighting a sentence with no explanation as to why lol i do feel bad bc english isn’t his first language and it definitely shows when he writes…but now he’s not even trying! I’m just so frustrated and now feel like I deserve first author. The post-doc and my PI are both male, and I’m a female. They both tend to side with each other, and I’ve seen my PI make the other female PhD students cry before. I need tips to approach this bc right now I’m pent up with anger and I don’t want to come off as unreasonable or emotional.

I'm sure we've all seen it by now. That blog post about ethidium bromide (EtBr) really not being all that bad. If you haven't, I've linked it right here. This post is constantly touted in this community as the be-all and end-all of EtBr safety, and I'm sort of left wondering why.

To sum the post up, it states that EtBr apparently doesn't have many harmful effects in the quantities it's commonly used in, and if it does, these effects aren't in humans. Personally, this article comes across as unnecessary, if not misleading, for a few reasons. First of all, it isn't a peer-reviewed article. It's just a blog post written by an independent, unaffiliated author. Second, some of the arguments are misleading (see directly below). Third, there is a lot of evidence that disagrees with the author's claims.

Just take a look at this paragraph, where the author suggests that EtBr is safer than other dyes due to its LD50.

Excessive concern about mutagenicity can make us overlook short-term toxic effects, and here EthBr is the safer dye. The reference above found that the SYBRsafe alternative was actually much more toxic than EthBr to the bacterial cells used in the mutagenicity tests. SYBRsafe was toxic at concentrations as low as 1 microgram/ml, whereas EthBr toxicity was not observed until 250micrograms/ml. The authors suggest that this is because living cells are much more permeable to SYBR green than to EthBr. But a MSDS for SYBR safe reports a LD50 for rats of >5g/kg, which is higher than that of EthBr (1.5g/kg).

Specifically, look at the bolded sentence. I'm not sure if this is a mistake or intentionally misleading, but it says that EthBr is safer because it has a lower LD50. In reality, a lower LD50 actually means a compound is more harmful.

More importantly, there is a myriad of evidence that suggests that EtBr is in fact harmful in multiple ways.

Ohta et al. notes that in an exogenous metabolic activation system, EtBr can induce frameshift mutations in E. coli, and even outside metabolic systems, potentiates substitution mutations caused by UV radiation. Furthermore, the paper concludes by outright stating that the authors "suggest that attention should be paid in the handling of nucleic acid stains such as EtBr, SYBR Green I, and acridine orange when they are used for electrophoresis gel staining."

Singer et al. finds similar results for frameshift mutations in the presence of metabolic systems:

Increases in the number of revertants per plate were observed with +1 frameshift mutation-indicating tester strains TA98 29, 30(maximum increases of 65.7- and 70.9-fold) and TA1538 (maximum increases of 99.6- and 60.7-fold) in the presence of S9 mix (Table 1). Increases in revertant frequencies were also observed with −1 frameshift mutation-indicating tester strains TA1537 (maximum increases of 15.0- and 14.9-fold) and TA97a (maximum increases of 4.0- and 4.8-fold) in the presence of S9 mix (Table 2). No increases were observed with these strains in the absence of S9 mix.

And for base substitution mutations:

Small, reproducible, dose-responsive increases in revertant frequencies were observed with base-substitution-indicating tester strains TA102 (maximum increases of 1.9- and 2.0-fold) and TA100 (maximum increases of 1.4- and 1.7-fold) in the presence of S9 mix (Table 3). In the absence of S9 mix, only tester strain TA102 showed reproducible increases in revertant frequencies (maximum increases of 1.8- and 1.7-fold). No increases were observed with tester strain TA100 in the absence of S9 mix or with strain TA1535 in either the presence or absence of S9 mix (Table 3).

Furthermore, while older research, Yajima and Suzuki review many effects of EtBr, ranging from its ability to impact the mitochondria because it is able to "inhibit or suppress mitochondrial RNA, DNA and protein synthesis in mammalian cells" and can lead to "swollen mitochondria, either with abnormally arranged or vesicular cristae, or with total disappearance of mitochondrial cristae." Furthermore, in the same paper, they show that "when introduced directly to the CNS of rats EtBr is toxic and produces a status spongiosus characterized by degeneration of oligodendroglia and formation of intra-myelinic vacuoles."

At the end of the day, what we know for certain is that EtBr isn't good for mammals, and current and past evidence suggests that it is bad for us. It seems like this sub can lose sight of that sometimes. Even the myth article devotes almost all of its space to pointing out that EtBr isn't all that bad, but has just one singular sentence about how you still need to be careful with it.

A single drop of the stuff won't kill you. But let's not forget that there are a lot of people here who are brand new to using this chemical, and to science as a whole. Being unnecessarily steadfast about the "EtBr isn't actually that bad" angle can misrepresent the truth to people who might not know anything else. Besides, at the end of the day, more safety isn't a bad thing.

Im paranoid. I just started this job and i log samples contaminated and non contaminated with asbestos. Analysis of asbestos, where i can see fumes, is not too far from where i’m seated. They don’t even comply to proper PPE???! Just lab coat and gloves??? Any advice.

I came across this article 'The Earth Is Round (p < .05)' from my colleague who is a biostatistician.

He says statistical significance of p-value is nothing to with clinical significance because it doesn't tell you about the real biological effect.

He claims that relative risk ratio, point estimation, and confidence interval are often more useful than merely saying 'p < .05'.

Then why do we still see 'statistically significant difference  (P < .05) in abstract of many journal papers in 2024 when this has been an issue for a few decades already?

It seems like in practice p-value is needed for publication and most people don't care about misuse of p-value at all - including PIs and journal editors.

It feels like talking against sacred p-value < .05 makes me the black sheep because a good portion of the results of my co-author paper will be based on P < .05.

hi! I recently completed a splenocyte suspension (live cell concentration was 6.74x10^7 cells/ml) and when I was prepping my cells to be frozen down, I added 1000μl of sterile DMSO (I wasn't given the concentration of the DMSO) instead of 100μl😭. My cells are currently stored in a LN2 freezer and won't be needed until nov 19 for a flow cytometry experiment. I was wondering if my cells are going to be okay, I know DMSO can be toxic to cells.

please lmk if this is the wrong place for this post! i'm very stressed out and too nervous to ask my TAs or prof. No worries if unable to help!:)

This might be a long shot, but am looking for some insight here!

The titrant in question is hydranal composite 5, which contains: Iodine, sulfur dioxide, imidazole, 2-methylimidazole, dissolved in DEGEE.

My medium is: 50 % comp 5 working medium (chloroform, 2-chloroethanol), 30% methanol, and 20% glacial acetic acid.

Those make up the reaction. I received some samples for water content that are supposed to be pure bis-(2-dimethylaminoethyl)(methyl)amine. They believe ambient moisture has contaminated their samples, as each sample is supposed to have <0.5% water. One of the samples I had a few issues duplicating results, but was able to get roughly 3.1% water. Their assumptions are correct. The other two samples are weird. For each of them, I was able to duplicate between 0.3-0.6%. However, they also duplicated results of 2.6-3.6% water. The higher water content data was first, so I don’t think they’re necessarily hygroscopic.

When I went to draw up the sample into the syringe for the fourth time, a white vapor (almost looked like smoke) started coming from the container and out of my syringe.

The weirdest part is post reaction. Every sample I have ever run will finish as a homogenous amber liquid. These last two samples separated into a white foam like precipitate and a clear yellow liquid. I already had to make a special medium because it is an amine. After bringing this up to the submitter, he mentioned there were concerns from the vendor that there were discrepancies with the cure kinetics. But he had no other info.

Thanks to anyone who read all of this and may be able to provide insight:)!

I have a multiple sequence alignment of 14 members of a family of proteins in CLUSTAL (.aln) format. I have secondary structure predictions for my sequences from PSIPRED, but I can't find an easy way to add them to the alignment and visualize them in JalView. Does anyone know of a good way to visualize secondary structure/predicted secondary structure for each individual sequence in an MSA?

I’m currently working on a science fair project where we have to essentially have microplastics somehow embedded into agar. I was wondering if there was anywhere I could find a procedure for creating a relatively homogeneous agar with either microplastics embedded it or plastic melted into the agar.

The plastic type we are planning on working with is polyethylene.

(Sorry English is not my first language)

Hi everyone, I have been working in labs for years as a student. Today the unavoidable happened, I was doing a Gram stain when the water bottle decided to act like a cannon, it made a huge splash, so now I am covered in safranin, I look pink as barbie. I need a miracle to clean this up, I know is almost impossible, but as a student I'm not going to be able to buy a new coat every time I stain one. Please tell me you know some trick to clean up this mess before Monday. My lab teacher told me to use bleach but I'm afraid of spreading the stain and making it worse. I will be forever grateful, Thank you

Do not come up to us and occupy us to try to sell your services when we are in the middle of poster presentations at a big conference. I am busy and I am only interested and focusing on my presentation and audience. You are costing me valuble discussions and insight.

That is all

I am doing a couple digests for different plasmids and I don’t think I’ll have time to run a gel. Can I just store the plasmids in the -20 after they are done incubating?