# Tag Info

10

I wouldn't autoclave this solution - sucrose will partly break down into glucose and fructose. A portion of the sugars will also caramellize and color the solution yellow to brown. If you need the solution to be sterile, I would filter sterilize it, although this can be hard because of the higher viscosity of the sugar solution. If you haven't seen any ...

4

Candianer's answer is a generally correct way of solving these problems but, in my opinion, overkill for this situation. All Nx buffers are mixed to make your life easier, and you will generally encounter 10x, 6x, and 5x buffers. 10x and 5x seem obvious, you just put them in so they make up a tenth or a fifth of your solution, but 6x seems to confuse people....

4

For any question regarding volume and concentration, you should consider the equation $C_1V_1=C_2V_2$. We can use it to derive a general equation for the addition of concentrated stock solutions. We want to find the volume of stock solution ($V_1$) to add so that its final concentration is 1X. Here's what we know: The initial concentration of stock solution,...

4

Thiol-Based Reducing Agents The instability of thiol-based reducing agents in solution is due to their propensity to form disulfide bonds by the following half reaction: $$\ce{2RSH -> RSSR + 2H+ + 2e-}$$ It is clear that disulfide formation requires: Deprotonation of the thiols to form thiolates (RS-). An electron acceptor. Therefore, solutions of ...

3

I found a standard protocol for the same here : http://vosshall.rockefeller.edu/assets/file/Vosshall%20Lab%20Mosquito%20Rearing%20SOP%20DEC%2012-2014.pdf Take a look at page no.8. They suggest to autoclave the sucrose solution.

3

Activity toward the desired substrate sequence is not the only concern in evaluating a restriction enzyme buffer system. In addition, you need to be concerned about so-called "star activity", or activity of the enzyme toward other, non-desired nucleotide sequences. For example, NEB supplies an enzyme-specific buffer for it's standard EcoRI, even though it ...

3

I remember using those for agarose gels as an undergraduate, though using them for PAGE doesn't make a lot of sense unless your bench is seriously out of level. Anyways, they can be called levelling tables and are used to promote uniform migration across the gel. Casting table also seems reasonable.

3

I routinely use 70% ethanol and/or IPA to wipe off plastics written on with Fisherbrand fine-tip marking pens and I find they don't come off easily even after multiple sprays. As long as the marker has had ample time to dry. The sharpie industrial "solvent resistant" markers come off immediately. So here I have a Corning 250mL bottle, and 3 brands of marker:...

3

This is hardcore going to come across as a SPAM answer, but I simply did a Google search: Laboratory Marking Pens from Ted Pella Statmark Pen™: resistant to formalin, ethanol isopropanol and xylene Secureline® Marker: water resistant; autoclavable; not suitable below 0°C (32°F) Secureline® II / Superfrost: resistant to xylene, ethanol, acetone and ...

3

I agree with Mike, but would like to add that if you are trying to do protein expression for purification, some detergents contain polyethylene glycol (PEG), which will readily bind to many proteins, causing shifts in protein size/weight and potentially effect activity or toxicity. In particular, I have heard that Liquinox can have PEG (depending on the ...

3

I can't tell if you're asking about glassware or work surfaces (hoods, benches etc), but... We use regular old dawn dish soap in my lab because what's more important than the soap you use to wash you're glassware is the water you use to rinse it. We teach our undergrads the 3-rinse-rule. After soaping, every item gets 3 rinses with normal tapwater (or ...

2

If you're just using it for hand washing, you probably don't need an ultra-concentrated solution. A very small amount of detergent goes a long way. (Think about it - what would you do with an ultra-concentrated solution? Probably squirt a small amount on the glassware and then add water.) What I've seen done is to make your "dilute" solution of Alconox, put ...

2

In our labs we just use something like palmolive or bleach followed by a 95% EtOH rinse and finally rinsing with DI water.

2

1) Yes, that's correct. 2) This is just a simple matter of applying the equation $C_1V_1=C_2V_2$. For congo red: $C_1=20\frac{mg}{mL}$ $C_2=0.04\frac{mg}{mL}$ $V_2=500\ mL$ I'm sure you and a calculator can figure the rest out.

2

I've used the ThermoFisher brand of CellTrace dyes. Specifically, I co-cultured two populations of cells, one with CellTrace Far Red in the APC channel and another with CellTrace Yellow in the PE channel. My choice was in part guided by a product review by another lab touting the relatively low cytotoxicity of these products. The protocol is quite straight ...

2

Looking at the container from the side, it's probably a situation like this: There might be some clear plastic wrap around the entire thing as well that you would need to cut/break.

2

That is an excellent question. I was a little confused at first because, without realizing it, you actually cited a perfect example of a biological process that manipulates metal: bone formation. Bone is made of hydroxyapatite crystal, which is a mineral whose main ingredient is, of course, calcium (metal). Now, to answer the how of your question; bone is ...

1

The difference in flame diameter between a Bunsen and Meker (or Fisher) burner really isn't that much, so I'm not sure how much larger the sterile field would be. On the other hand, Fisher burners can be tuned to be much hotter than standard Bunsen burners, so that may impact the size of the field as well. But, at the same time, they use more fuel, so you ...

1

There is a number of different dyes possible, as you can see in this figure (from here): A good overview can be found in the "Selecting Reagents for Multicolor Flow Cytometry" application note publication from BD (in reference 1) and also the Fluorochrome Specifications from BD (reference 2). References: Selecting Reagents for Multicolor Flow Cytometry ...

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