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

How long can you store a reconstituted TSH sample in a refrigerator?

We have reconstituted human TSH hormone (Sigma), that we use in our immunoassay system. How long can we keep the same at 4 deg before any sort of loss in activity is observed? We do multiple test...

09 October 2018 4,450 0 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

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

Why are the velocities so high in my Boussinesq approximation Fluent simulation?

Hello, I have a mechanism where air rises due to convective flows. In this simulation, nothing is driving the air except this. I understand that the Boussinesq approximation only works for small...

02 March 2021 4,910 3 View

Precipitate after adding laemmli buffer to protein solution containing Potassium Acetate?

Hi, I am running a size exclusion chromatography experiment with a buffer containing Potassium Acetate as a salt. I analyse these fractions through SDS-PAGE. After boiling my SEC fractions in...

01 March 2021 2,622 3 View

Benefits of the 24 welled plate?

We have always used the 96 welled plate, the 48 welled plate but apparently there is much evidence on the 24 welled plate and above all its benefits.It states it is the same you would use on ELISA...

28 February 2021 1,149 1 View

Why do the air flow results vary totally when adding scalar in CFD ?

Dear All, We are using Autodesk cfd to calculate the air flow in a single sided naturally ventilated room, where air flow depends only on buoyancy due to temperature difference between inside and...

25 February 2021 9,602 4 View

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

24 February 2021 1,365 3 View

Is is possible to pole with corona poling pellets of the sample material instead of thin films?

As it is highly probable that pellets will have a higher degree of air gaps and voids than thin films, is it possible to pole the samples with corona poling nevertheless? Or is there the...

24 February 2021 1,349 1 View

Can two EC50 values with different hill slopes be compared?

Hello, I fit a classical dose response curve Y=Bottom + (Top-Bottom)/(1+10^((LogEC-X)*HillSlope)) to my data (not related to inhibitors etc). The model I use is purely qualitative but it fits...

23 February 2021 8,155 5 View

Have you ever experiencing air vent trouble in fermentation process?

Dear all, My research group is currently working with a 12-litre fermenter. Somehow, if we do the fermentation for more than 20 hours, the process will be more prone to contamination. Our current...

23 February 2021 1,908 2 View

Help with assigning pressure boundary conditions in FLUENT on a large structure?

Hello, I created a very tall tower (>1000m) and applied pressure boundary conditions at the inlet (bottom) and outlet (top) that correspond to the pressure are their relative altitudes....

22 February 2021 9,972 4 View

What type of pressure sensor are usually used in microfluidics?

My team is designing a dual channel microfluidic chip that runs air and water. I think we've decided on the NE1000 syringe pump for it's versatility and feedback control. We will be ordering the...

18 February 2021 9,928 2 View