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Questions related from Xin Pin
How to determine LoD, LoQ, Linearilty, Cutoff, Expected values for an IVD assay (infectious disease or physiological state monitoring eg. hormones). Has anyone preformed these, can you explain...
02 February 2020 3,081 3 View
Hi, I have come across an IVD quantitative assay for C-peptide where both anti analyte biotin-conjugated antibody which binds to Strep coated wells and HRP conjugated anti-analyte antibody was...
01 January 2020 3,731 3 View
If a patient has been exposed to a particular type of AAV already, their immune system might have developed antibodies that could neutralize the effects of that vector. How do I know if a...
03 March 2019 5,139 7 View
How do i define the exact substrate concentration for 1 U of enzyme. Say my protein concentration after purification is 1mg/ml. If i take 500µl of it (which has 500µg) to convert the...
02 February 2019 425 5 View
"The homogeneous "add-mix-measure" format results in cell lysis and generation of a luminescent signal proportional to the amount of ATP present. The amount of ATP is directly proportional to...
11 November 2018 4,058 2 View
After reviving the cells from -80C and seeding the cells ~1 million in T25 flask when the cells reach 80% confluency then if I passage/subculture the cells for eg. spleen (finite) or CHO or...
07 July 2018 552 7 View
Can surfactant and defoamer be used at the same time?. Surfactant (an amphiphilic) works based on reducing the surface tension of water binding thru hydrophobic interaction and hydrophilic...
01 January 2018 3,978 5 View
Standard cloning strains DH5α, Top10, Novablue or α-Select Gold contain lacZΔM15 deletion mutation? The lacZ gene in the plasmid vector complements the lacZ deletion mutation in the host E. coli...
01 January 2018 3,584 7 View
If I had 28million cells/ml (A) and require 11million cells/ml. I add 392.85 ul from (A) + 607.15 ul of 19.4% (since it is 0.6 times more) DMSO. Now final Conc. of DMSO is 10%? Explain with...
12 December 2017 3,016 1 View
In western blot why do we dilute primary antibody in 1% skimmed milk so that if there are any antibodies against blocking agents they get blocked? but why would they be antibodies against skimmed...
11 November 2017 7,640 7 View
Coated antigen conc. used 50ng/100ul antigen1 (is an antibody) conc. 100ng/100ul + purified Mab conc. 1000ng/100ul antigen1 is an recombinant Mab with human Fc region against peptide conjugated...
11 November 2017 4,685 7 View
Why do they refer protein oxidation as Chlorination, Nitration?In general, oxidation is the loss of electrons/Hydrogen and the gain of oxygen.How does Chlorination (addition of Cl) or Nitration...
10 October 2017 4,212 7 View
I noticed so much inconsistency in the indirect ELISA for cell culture supernatant and also for purified MAbs. Although some clones follow serial dilution say 2-3 out of 8 clones on the same...
10 October 2017 1,568 3 View
When I see an OD of 3 does it mean at 450nm there has been so much (oxidized TMB) absorbance? How does the oxidized product gets quantified exactly! (not by interpolating with standard curve) by...
10 October 2017 565 5 View
Rabbit monoclonal antibodies "recognition more diverse range of epitopes" what does diverse range of epitope mean? Eg. I have hybridoma clones all secrete identical antibodies against single...
10 October 2017 6,168 6 View
What is the correct way of choosing competent cells (cc) volume during cc preparation (58ul cells + 2ul plasmid) based on cc concentration or ration? NEB recommends required ration is 1:25 and...
09 September 2017 9,911 10 View
What is the difference between 5X master mix and a 1X mix? I know its 5 times more concentrated. Eg. if the user needs 12mM MgCl2 and if the 5x master mix provides 25mM I need to dilute? what is...
09 September 2017 9,813 9 View
If they are more than one component involved in preparing a buffer then it is expressed in X? Why are buffer sometimes expressed in X rather than molarity
09 September 2017 5,298 0 View
"Primer Melting Temperature (Tm) by definition is the temperature at which one-half of the DNA duplex will dissociate to become single stranded and indicates the duplex stability. Primers with...
08 August 2017 9,009 14 View
The procedure involves lysis of nuclear membrane and bind DNA on to the column. But DNA is tightly packed with histones as chromosomes are we disassociating DNA from histones? or extracting...
08 August 2017 7,313 6 View
After cell fusion and screening for hybrids that secrete mAb against the antigen. Usually, plates are coated with antigen concentration 1ug/well and 100ul of cell culture supernatant as a sample....
08 August 2017 5,248 13 View
DEAE has a pKa 6.9 (DE52) Tryptophan synthase, alpha subunit has pI 5.31 Wash buffer & Equlibriation buffer are same pH 7.8 (10mM phosphate buffer 4mM Na2EDTA 1mM DTE). Pellet fraction...
08 August 2017 6,919 11 View
After amplifying a promoter sequence, transgene and activation domain and polyA signal. I plan to insert these constructs into a pUC19 vector with a downstream promoter CMV associated with GFP and...
08 August 2017 3,676 12 View
