soconfused

Can anyone help me getting full text of this article, please? Thank you a bunch! http://www.ncbi.nlm.nih.gov/entrez/query.f...5&dopt=Citation Biochemistry. 1997 Feb 11;36(6):1467-78. The divergent 5' termini of the alpha human folate receptor (hFR) mRNAs originate from two tissue-specific promoters and alternative splicing: characterization of the alpha hFR gene structure. Elwood PC, Nachmanoff K, Saikawa Y, Page ST, Pacheco P, Roberts S, Chung KN.

The stock i bought is defined in 12% and not in molarity. Any ideas?

What is the unit of 10,000 and 1,000,000 in this case? mL or L? Should i not consider the densities of both solute and solvent when both are in the liquid phase? Besides the one i use is Sodium hypochlorite (NaOCl), with a stock concentration of 12% . Will you please show me how to calculate 10,000ppm hypochlorite from a 12% stock? It just says the vapor density and not the density for the solution. Do you mean; 1 p.p.m. = (mol.mass of solvent)/(mol.mass of solute) x mG/L? It seems like you forget something before mG/L, because i don't understand the formula. Thanks.

I have to make a solution of 10,000ppm hypochlorite, since 1ppm is like 1mg/l for a solute in water solution. Does this mean that i have to add 10,000mg hypochlorite in 1liter water? If hypochlorite is in a liquid form, should i take into account its density and from that to find the volume i add to the water to get a totol of 1 litre? Besides; Is 1ppm the same like 1mg/l ? Or does it depend in other factors like both the densities of the solute and solvent? Thanks for any inputs.

Uh, i never thought that they are different things. I would test up or down regulation of gene expression. Which one should i use? THanks.

good links and info of RT- PCR? appreciate for any inputs.

hi guys! what types of cells is a mammalian cell? i know this is maybe a "horrible" question, but i find it hard knowing the different cells under this category cell. i have looked in the net, but don't find any site where they explain about this type of cell. so hope for some ideas. thanks!

hi guys! i have difficulty in understanding this sentence, since English is not my language. here it is : "The elution volume (Ve) is the volume of buffer before which the peak of protein elutes." hallo! yes, i don't get it. does it mean Ve of that protein is the volume of the buffer before the UV-absorbance of that protein or does it mean that the volume of the buffer to the middle of the peak? p.s! UV-absorbance and peak are different things here. thanks for helping!

wrong forum!

thanks very much for your sharing, Frostrunner!

chromatography: we have to collect the fractions from the column. i wonder what is the difference between; flowthrough fraction, wash fraction and eluate fraction? i think i know what it means with eluate fraction, but what about the other two? hope for replies! thanks a bunch!

thanks alot Dave and Woxor!

hi skye! are you sure column cross-sectional area (cm2) has this formula? thanks!

hi guys! i am doing the chromatography. in scaling up i have to increase my volumetric flow rate but maintain my linear flow rate. my problem is i don't know how to calculate the column cross sectional area (cm2). i have asked the people in the math forum, but it seems like we get nowhere, so i hope you guys who work with this area can tell me how i can calculate it when the radius of the column is 2cm and the height is 5cm. Linear flow rate (cm/hr) = volumetric flow rate (cm3/hr) / column cross-sectional area (cm2) thanks a bunch!

so what is cross-sectional area?

hi Dave! are you sure that cross-sectional area is the same like the areal of the column?

hi guys! thanks for sharing, but i don't think we are right, since the answer must be in cm^2, which means it is not the volume of the column we are looking for. by the way what does it mean with cross-sectional area? is that the areal of the column? yeah! and thanks for being nice to me due to my first visit here

hello guys! i have a column with a shape of a cylinder. the radius is 2cm and the heigh is 5cm. i have to calculate the cross-sectional area of the column. i wonder what is the formula and how is the calculation? it has been a long time since i last had my math lectures, so i really hope for some help! thanks alot!

what is the difference between a non-reducing and a reducing buffer? :uhh: and what does it mean with non-reducing and reducing? thanks a bunch!

all i learnt about protein expression till now is gone, may i say, just because an explanation from my professor...i just hope that he was not right about this, since it turns my "world" up side down! the aim was to investigate the different expression degrees of the yeast genes. we used S. cerevisiae. we transformed the yeasts with a transposon carrying a lacZ gene. by homolog recombination the transposon with the lacZ gene was inserted into the different yeast genes. we selected for blue colonies. we got different degree of the blue colour. it showed that we got less blue colonies than expected. i asked my professor and he explained; -> because 80% of the yeast genome codes for active genes ( open reading frames without non sense stop codons) if the transposon was inserted into the active genes then lacZ can't be expressed even if the insertion was in frame with the active genes! yes, this was what he told me. from my knowledge i thought it does not make any different which genes a DNA segment is inserted into. as long as the fusion is in frame between the different genes, then expression would be! now he said that it does not include active genes. WHY CAN'T ACTIVE GENES GIVE LACZ EXPRESSION? BTW what kind of genes gave the expression of lacZ we got in this experiment? how can they give the expression of the lacZ??? thanks so much for reading and help!

hello everybody! what does ORF means? i am stucked at this word, so hope for replies! thanks a bunch!

thanks!

i am not sure if this is the right place to post this question, but since it is about proteins then here i go... about proteomics: the IEF dimension is performed using 7 cm or 18 cm IPG strips of selected pH range (3-10, 4-7, 3-6, 5-8, 7-10, 6-9, 3-7, 6-11, 3.5-4.5, 4-5, 4.5- 5.5, 5- 6, 5.5- 6.7). my question is what decides the selection of a specified pH range? i have looked for answers, but can't find any. it would help alot if anyone can tell me. thanks! wait for replies!!!!

Hello everybody! This is one of the biggest challenges I have ever faced I hope that you have dealt with this matter before and hope that you can give me some advice and help. Thanks very much in advance! the recipe: Sodium phosphate: Each ml contains 276mg of monobasic Naphos (NaH2PO4), and 142mg of dibasic naphos (Na2HPO4). 93 mg of phosphorus/ml = 3 mmol. 92 mg of sodium per ml/23 = 4 meq/ml. Osmolarity: 7000 mOsm/L my problems: a) as the recipe states 1 ml solution contains 276mg of monobasic Naphos (NaH2PO4), and 142mg of dibasic naphos (Na2HPO4). then how come they only get 93 mg of phosphorus/ml = 3 mmol????? It seems like we are dealing with a buffer ( NaH2PO4 and Na2HPO4). b) again, how come they only get 92 mg of sodium per ml/23 = 4 meq/ml??? c) how many particles do i have in this solution? My point: NaH2PO4 -> Na+ + H2PO4- I am not sure if the dissociation stops here or if H2PO4- will dissociate more and give more particles???? Na2HPO4-> 2Na+ + HPO4(2-) like the above, will H2PO4- dissociate more and give more particles???? then what is the total number of particles we have in solution? How can you calculate the osmolarity when you have the combination of NaH2PO4 and Na2HPO4? hope very much for advices! thanks alot!