Heba Huessin

65 Questions 31 Answers 0 Followers

Questions related from Heba Huessin

How to remove hidden codes in word on mac when using mendeley?

I am using menedely and this required by the journal and I tried everything. I assume removing the hidden codes will remove that grey shade of the references? One recommendation online is to right...

01 May 2022 2,209 2 View

Importing paired FASTQ file into qiime had errors. any help?

Hi. I activated qiime 2 2019, prepared a folder named '6 sample file' to try data import which has metadata, manifest, and 6 data sequences as in the picture. I received this error. maybe as...

22 October 2019 5,181 2 View

Do we must write/fill ALL items of STROBE checklist in our manuscript?

is STROBE a reporting tool? so we need to make sure we reported every item of the checklist in our manuscript before submission? or we simply can mention that some items are not applicable to our...

20 August 2018 9,410 2 View

What is wrong with convenience sample cross-sectional studies?

I got many comments from reviewers that my sample is considered a convenience sample (easy to reach). In my opinion, convenience does not mean non representative. It is normal if a group of...

20 August 2018 5,600 5 View

What bone biomarkers (proteins) to be used to evaluate bone regeneration in vitro using western blotting?

What are the most popular bone biomarker proteins for bone regeneration please? thanks in advance.

26 December 2017 2,068 3 View

Hi what is risk of bias tool for a systematic review of retrospective studies please?

what is the risk of bias tool for retrospective studies, if any.

24 December 2017 4,374 3 View

How to use TargetScan to identify target genes for miRNAs?

Greeting I did miRNA profiling and I need to have idea about the function. when I enter miRNA name in TargetScan, hundreds of miRNAs appear. My work is about cancer, so I am concerned with...

09 November 2017 2,625 7 View

How to edit a style in mendeley?

i logged into csl.mendeley. i searched the sty;le which is APA and now want to edit how the author name is written. i don't know how to edit. attached a pic. thanks in advance.

11 March 2017 9,718 2 View

What statistics test we use for cell proliferation assay comparing different concentration of drug to control untreated cells?

I worked on cancer cells. Added cytotoxic drug at three different concentration. Each concentration added in six replicates. I incubated the cells after adding PrestoBlue. Then read the flouscence...

01 February 2017 5,005 5 View

Can systematic reviews be done based on non randomized trials?

And if yes, what the tool of evaluation and level of evidence of such review? There are trials comparing effect of drug or technique on normal versus diseased so randomization is impossible.

23 January 2017 9,396 8 View

Which statistics test we use for western blot bands quantified by software studio image?

Since we don't have mean or SD as I don't have population, which test to use? Papers mention student test but don't know how. I have two bands for each marker. I quantified to get percentage...

17 October 2016 729 1 View

If I centrifuged cells after trypsinization and got no pellet, how to harvest the cells?

I don't have much cells. I centrifuged and did not get true pellet. Just pieces of white material. Now my cells were in about 6 ml medium. If I aspirate supernatant, they will have some cells....

23 September 2016 4,160 4 View

What is the least volume of RIPA lysis buffer can be used for 100 mm dish to get higher protein conc?

Some proteins did not show in western . I used 300 ul lysis buffer last time for the dish and got 2 ug/ul protein. I used high conc of cyclin d 1:20 and still did not show so I plan to decrease...

21 September 2016 3,728 1 View

How to calculate sample protein based on standard protein curve in BCA?

I made curve for standard protein 10-60 . How to calculate the sample protein based on absorbance of BCA? Which equation or software you use? .

13 September 2016 5,196 11 View

How to convert centrifuge speed values from xg to rpm and vice versa?

I pellet my cells at 1000 rpm and using RNA isolation which require 12,000 xg. How to convert this 12,000 xg to rpm .

12 September 2016 9,619 42 View

How long do you keep cell lysate on RIPA buffer and do you sonicate cells?

Protocols differ in time to incubate cell lysate on buffer after scraping w spatula. How much time u keep cells before centrifuge? And do u do this step: Sonicate the lysate (Branson Digital...

13 August 2016 191 1 View

In western blotting, what protein info shall we know before doing cell lysis?

Is cell lysis protocol same for all proteins?.

29 July 2016 1,068 3 View

Anyone made a container similar to Mr Frosty to freeze the cells?

my lab does not have Mr Frosty. I freeze cells at -20 then -80, but wondering if anyone could developed a container similar to mr frosty using ethanol?

15 July 2016 9,219 3 View

Can mycoplasma contamination happen without the spakes shape appear under microscope?

I suspect mycoplasma as cells stopped growing but I can't see the characteristic shape under microscope. Did this happen to anyone?.

11 July 2016 4,150 2 View

What are the causes that may cause the cells not to double after four days of incubation?

my cells doubling time around one day and i cultured them four days ago and they did not double or increase in number. they did not die neither. may be the medium is not enough? .

05 July 2016 1,665 9 View

Any tips for taking pictures of cell culture under microscope w or w/o phone camera?

My lab microscope not connected to computer and I need to take pictures of the cells in different growing stages. Someone recommended the regular phone camera. Any tips for better details or any...

24 June 2016 7,402 3 View

Can I use PrestoBlue cell growth proliferation assay on same plate three times?

I added the drug. I want to test cell growth. I will add PrestoBlue reagent to cells and read using micro reader on day one. I also want to test effect of drug on day two and three. Can I just...

14 June 2016 5,102 1 View

How to prepare cell line for flow cytometry? How many well plate and how many cell per well?

The goal of the experiment is to analyze cell cycle after adding a drug.nthanks

30 May 2016 5,815 5 View

How do you count cells without trypan blue test?

Hi my lab protocol does not use trypan blue to count the cells. In my past lab, I used trypan so I could count the cells which did not take the blue dye. So how to differ dead and alive cells when...

23 May 2016 7,604 2 View

What range or value of Confidence interval considered narrow and what range considered wide?

When to describe a confidence interval as narrow, and hence a large sample size or wide and hence a small sample size? Thanks

19 February 2016 8,544 5 View

Can we conduct meta analysis based on binary outcomes?

If the papers use binary outcomes ( increase/decrease) and not mention any numerical data, can we still conduct meta analysis?

03 July 2015 3,840 6 View

What is the minimum number of studies to be included in a systematic review?

If the treatment is still a new one with limited studies, what is the least number of studies can be included in a systematic review? Also, do all studies be of same study design? Ie. RCT or can...

08 February 2015 9,070 37 View

What determine inclusion and exclusion criteria of a systematic review?

On what basis the author choose to include or exclude certain papers in his systematic review? Why to choose certain age or gender to include?

08 February 2015 9,519 14 View

How can we know that a non inferiority drug trial is as such ahead of time, i.e. before it is conducted?

how we can know before conducting the experiment that it will be non-inferiority or superiority trial? How we can know that the drug /treatment is superior or just equal ?

22 January 2015 1,753 5 View

Is Effect size or CI a more reliable as an alternative to P-value?

Some advocate for effect size, and others for confidence interval. Which is more reliable?

21 January 2015 2,961 5 View

Why we can't use risk ratio in case control study?

Can anyone explain why we can't use odds ratio in cohort study using simple logical approach rather than statistical one? I read that the investigator can change the number of control and...

09 January 2015 5,713 2 View

How to order primer for miRNA qPCR?

Hi. If I want to do qPCR to certain miRNAs, do I send the company the name of miRNAs or sequence for primer or sequence of miRNA? And do u know a company? .

01 January 1970 6,891 3 View

Do we need to report the western blot data into genbank or any other database bank?

some journals ask that protein or DNA must be reported and have accession number. I don't know if this applied too western results.

01 January 1970 6,575 3 View

How long RNA stored in -80 be stable for qPCR?

It was RNA from oral cancer cell line extracted by Qiagen .

01 January 1970 6,242 6 View

Anyone has a checklist for cell culture lab design requirements ?

01 January 1970 4,337 5 View

How you transfer cell line vials on plane, especially out of USA?

What the regulations to carry cell line on dry ice?.

01 January 1970 9,982 1 View

How to perform spectrum scan in multi plate reader to determine lm1, lm2 for my sample for prestoblue?

prestoblue not work for one of my cell lines. i use absorbance 570 and 600 but need to perform spectrum scan on multi plate reader but dont know how.

01 January 1970 3,487 1 View

How mixing cells (same cell line) but different vials and storing conditions affect the results?

i, mistakenly, mixed two flasks of t-25 into t-75 flask. both same cell line but got from different vials. one was slower than the other. how this will affect my results?

01 January 1970 3,004 3 View

If cell line resist trypsin, would you increase typsin amount or time?

all my cell lines detached within five minute trypsin except one. i dont know which is better for cells and less harsh: to increase amount of trypsin from .7 to 1 ml for t-25 flask or to increase...

01 January 1970 2,914 7 View

In Cell proliferation assay (PrestoBlue), is it normal that medium alone reading larger than the reading of the treated cells?

I did PrestoBlue cell growth and proliferation assay and the numbers of drug group is smaller than the medium so the treated group-medium is negative. Does this mean all cells died ? But under...

01 January 1970 2,350 4 View

What is the optimal duration to keep the FBS in a cell culture medium fresh?

I know that the prepared medium shoul be used within three weeks only of prepration then discarded but a college told me that the FBS is even more sensitive and should not last more than two...

01 January 1970 7,845 3 View

How to thaw RIPA lysis buffer?

I have the big brown bottle of RIPA and it takes ages to thaw. How to thaw safely? I know I have to aliquote but concerned to put in eppendorf as it light sensitive.

01 January 1970 5,814 4 View

How to use miRNA modulation as a cancer therapy?

some miRNAs decrease proliferation of cancer cells. in this case, does the use of thearpuetic agnets which upregulate these miRNA can help treat cancer? and what is the difference between...

01 January 1970 3,792 2 View

How label eppendorf, centrifuge tubes especially if you gonna put in water so sharpie disappear or if too small to write on as centrifuge tube?

this seems trivial question but label disappear on boiling and samples may mix.

01 January 1970 8,540 4 View

How do you recognize apoptotic cells from microscopic picture ?

In first picture (low magnification), can we consider the two black cells on top corners apoptotic? In second picture is high magnification of one of the cells and also appear dark.

01 January 1970 850 4 View

Can we do protein quantification using BCA/Bradford without repeating standard protein curve?

i did BCA many times and standard protein absorbance very similar. Eg: 60 ug gives about 30 absorbance and 40 2.3 and same for the whole curve. It won't change as I use same concentrations . Can I...

01 January 1970 6,308 3 View

Western blotting showed no protein band. Could cell lysis step failed or the lysis buffer was too much?

On imaging, there was very faint lines. I am not sure they considered bands. I used beta actin and p-53. Is it possible that cell lysis not worked at all? I did BCA and got reading for the...

01 January 1970 870 3 View

How many cells you seed in Petri dish for western blotting for three days treatment?

I seed cells in dish then next day apply treatment then after three days collect protein. How many estimate cells to seed.

01 January 1970 7,670 3 View

In western, can we strip membrane more than once? And any tips for the stripping solution?

I need to repeat unfortunately for many reasons: either conc of antibody or expired ab or human error. I may need to use same piece of membrane for two more trials. Is it possible? .

01 January 1970 1,443 3 View

How do use maximum amount of antibodies in one gel of western?

I use biorad marker . Most antibodies m wt around 40/50. I plan cut horizontally to use 3 antibodies per membrane but the m Wt so similar. Can't cut vertically as I have 7 samples. Attached picture .

01 January 1970 9,261 3 View

In western blue, what average dilution for these antibodies : cyclin a and d, caspase 3,9, PCNA?

I don't know if I shall use the dilution recommended by the company or the higher concentration, the more possibility protein will be detected?.

01 January 1970 6,753 3 View

How to store membrane to re-use it in western plot in case I want to adjust antibody concentration?

I don't know the optimal antibody concentration so I may not reach good result and need to try another concentration (higher) using same membrane the next day so need to know how to store the...

01 January 1970 7,221 1 View

Could this be a mycoplasma in cell culture? And what the other picture is?

Is first picture mycoplasma? Or just ink image from writing on flask? i believe the second picture (has regular circles) is from the microscope lens. But don't know how to get it out of the field.

01 January 1970 6,098 2 View

In micro BCA assay, how to dilute BSA standard? what do use for dilution and what percentage?

01 January 1970 5,280 4 View

How to aliquote positive and negative control cells for annexin v apoptosis for flow Cytometry ?

Attached a scheme for the groups (flasks): one flask positive control, one group treated with the drug, one group (flask) treated with medium (live or negative control). I need to use BD apoptosis...

01 January 1970 839 3 View

In flow cytometry, when trypsin to get the cells, few cells remain in well as usual, will it affect cell equality in number of cells between groups?

01 January 1970 8,532 3 View

What is the advantage of using hand made gel than ready gel in western blotting?

Other than that hand made gel is cheaper, is there any other advantage ? . Or better to use ready? .

01 January 1970 5,783 3 View

What may cause double bands in western blot?

Attached a pic. I don't know why this happened. BTW, this is done on stripped blot. But first time the blot was negative .

01 January 1970 6,774 2 View

If actin did not show in western due to non working antibody, but other proteins showed, is it a must to repeat all proteins with new western plot ?

My proteins appeared but actin not. May be I forgot to add the secondary antibody to the wash buffer or primary ab actin was expired. So I need to repeat the all antibodies with new gel run? I...

01 January 1970 527 3 View

In protein collection from cells using RIPa, what can cause (no-pellet) after centrifuge and how affect western?

i centrifuged at 14000 rpm 20 min but not pellet formed.

01 January 1970 7,086 5 View

For caspase 8, P53, cyclin D protein, what are their expression level?

I am doing western for these proteins and need to know expression level to determine how much cells to grow and how much lysis buffer.

01 January 1970 7,952 4 View

Western blotting theory questions?

Hi. 1. Why do we use internal (negative ) control as actin? 2. Why we don't attach the detector enzyme directly to primary antibody?how secondary ab amplify the signal? 3. Why we need to separate...

01 January 1970 1,799 3 View

Any recommended resources to start learning Next Generation Sequencing idea and application?

especially websites and youtube please. TIA

01 January 1970 712 4 View

How to determine "effect size" in order to calculate sample size?

and is effect size can be obtained from p value.

01 January 1970 2,598 5 View

What is the cut-off for positive and negative likelihood ratios?

What is the cut-off for positive and negative likelihood ratios to assess a new diagnostic test? In all conditions, contextualization is the key but having a reference cut off would help the...

01 January 1970 1,461 1 View