Why are there very few health devices based on electrochemical sensors or other simple assay technologies?

Electrochemical sensors have an inherent advantage for being simple, cheap (glucometers), especially for nucleic acid assays. Yet there are very few health devices in the market for point of care...

11 December 2019 8,547 3 View

How can we stabilize purified humanThyroid Stimulating Hormone (hTSH) in buffer, without the use of albumin or other large molecules?

We use purified hTSH (in PBS), but have issue with stability of the sample. Since the purified hormone is highly unstable the activity reduces drastically at room temperature. We had added BSA to...

06 July 2019 8,619 4 View

What are some good methods (other than Plasma/Ozone/UV treament) for generation of reactive molecules before using APTES for coating in microchannels?

We do not have a system for oxygen plasma, corona discharge or ozone in our lab. We wanted to create reactive surface for our immunoassay on PDMS, such that it can bind to APTES. We have been...

03 April 2019 3,379 3 View

How likely are antibodies in buffer to get degraded by protease contamination due to casual handling?

I know it could be a little naive question. Wanted to gather views and experiences on likelihood of stock solutions of antibodies, in PBS (with sodium azide) likely to suffer degradation due to...

02 March 2019 5,073 7 View

What can be the reasons that you get a lower reading for samples than control for an immunoassay?

We are performing a microfluidics based immunoassay reaction, with a modified system. We have been getting lower readings for our spiked samples, compared to control samples. For example, if...

31 December 2018 6,351 3 View

What can be the reason for decreased ELISA reading of reconstituted TSH hormone?

We recently got TSH hormone from Sigma. On the first day, we ran our assay, and the results were fine. On the second day, the activity has somehow reduced by 90%. How is this possible? We...

07 August 2018 348 2 View

What can be done to increase efficiency of reconstitution of desiccated microparticles in a microchannel?

We are trying to desiccate BSA coated polystyrene microparticles (2-3 um diameter) in a plastic microchannel blocked with BSA/Casein + Tween 20. When we are trying to reconstitute the particles,...

07 August 2018 8,638 0 View

What would be the best coating buffer for covalent coating of TSH antibody (IEF Range: 5.8-6.9) on a functionalised PMMA surface?

We are optimizing the assay parameters for our TSH immunoassay. We had been using a 7.4 pH PBS buffer for antibody coating so far, but now want to evaluate if changing the pH of the coating buffer...

06 July 2018 3,644 2 View

Best method to desiccate reagents and polymeric microparticles in a microchannel?

We wish to desiccate protein coated polystyrene microparticles with some other proteins inside a microchannel. We tried doing so using normal air drying (non-sterile air, from a blower). But when...

05 June 2018 3,806 1 View

Which is a better method for protein immobilization in a PDMS microchannel - 1. APTES and Glutaraldehyde based binding or 2. Protein mediated binding?

The first method is silanization of PDMS surface with 50% v/v in ethanol followed by treatment with Glutaraldehyde which presents a site for antibody binding. In the second method BSA is passively...

03 April 2018 5,917 5 View

What degree of missing data in a particular case/participant results in Expectation-Maximisation no longer working?

I'm dealing with a mediation model and am using the PROCESS module in SPSS. Due to SPSS and PROCESS being limited in the imputation methods - being unable to handle multiple imputation - the other...

02 March 2021 4,362 1 View

How to grow E.coli on the low salt LB agar plate with 50 or 100ug/ml of Blasticidin?

Hello, I would like to ask how to grow E.coli which resists 50 or 100ug/ml of Blasticidin. I have tried many methods by using low salt Luria-Bertain(LB) agar plate. However, no colonies grow. Let...

01 March 2021 2,027 2 View

Is anyone familiar with the cyclic compressive fatigue testing (BS EN 12697 - 25) ?

I would like to get more information on the cyclic compressive fatigue testing (BS EN 12697 - 25) which is typically done for bituminous material in pavement design. Any one can advise on the...

28 February 2021 2,004 3 View

RIA. How to measure?

When you use RIA, with a control the unknown sample with antibodies, you bare in mind the binding sites of the antibodies. However you still need to measure labelled antigen (radioactive) and not...

28 February 2021 2,133 3 View

What is the most suitable resuspension buffer for TCA/acetone precipitated protein?

I need to extract protein from fermented carbon sources for Bradford assay. Most researchers experiencing insolubility of pellet in resuspension buffer. Please assist me to select most suitable...

26 February 2021 7,129 3 View

EMSA troubleshooting. Protein-DNA complex not migrating, cold probe lane with multiple bands. Can anyone help?

I'm running an EMSA to show the DNA binding activity of recombinant proteins versus the Wild type. Previous assays run by my research group using a different test system show the protein-DNA...

24 February 2021 8,325 1 View

How to interpolate from a time-series database ?

Hi, I am having trouble with a problem, in the field of Optimal Control and the generation of optimal time-series. Let's consider a system, whose dynamics are represented by dx/dt =...

24 February 2021 9,105 2 View

Standard curve shifting over time. How do I stabilise the ELISA?

24 February 2021 1,365 3 View

Can we recognize signs of the "volatility clustering" property of a time series in its time domain plot?

My purpose is to recognize the volatility clustering property without statistical tests such as The Lagrange Multiplier (LM) test.

24 February 2021 4,150 3 View

How to run raise regression in R?

if anybody know how to run raise regression in r, and raise parameter selection, please help me

24 February 2021 8,199 1 View