Week 3

My partner Liz and I are furthering our investigation of bright field vs phase contrast imaging through video.

RET @ BU Week 2

This week started out with many questions. Upon assessing our accomplishments from week one, my colleague Liz and I have many questions that can be developed into possible investigations.  Our newly acquired understanding of Ashwin's (BU Ph. D candidate) phase contrast microscope rendered it possible for us to develop testable hypotheses within the time frame we are working with.

My week one blog ended with questions about about using the microscope as a diagnostic tool (RDT).  However, our time frame, advances in the image processing of the microscope in question, as well as certain lab protocols (access to bodily fluids) forced us to re-think our hypothesis. Given that we use regular brightfield microscopes in the classroom, we thought that it would be a good idea to investigate brightfield image versus phase contrast imaging in the lab.  Ideally, we hope to generate images such as the ones on the left as part of our collected data.

 Differences in light absorption between living cells and their surrounding nutrients are often negligible.  In other words, you can't tell where the cell membrane ends and the organelles begins using brightfield microscopes.  Phase contrast microscopy uses the very small refractive index of different cellular components and their surrounding to produce contrast in these organelles and similar transparent specimens.  The simplest example of refractive index can be observed in the image on the right.

Among others, here are some of the hypotheses we plan on investigating:

1. General observation of the specimens without stain in brightfield vs. phase contrast - How does the look of these specimens (Amoeba, daphnia, euglena, paramecium) differ?
2. Depth of view: cell membrane vs. organelles or cytoplasm. Can cilia & flagella be observed in brightfield and/or phase contrast?
3. Organisms phototaxis behavior (LED in phage contrast vs. bright field)

• What wavelength of light do euglena exhibit positive or negative phototaxis (toward or away from)?
• At what speed do euglena move toward or away from the light source (brightfield vs. LED)?

"I'm going to be a .... I don't need all these science courses." 
Note: The phase contrast optical theory was developed in theoretical physics.  Yet, it led innovative developments in seemingly unrelated disciplines, us as biology and medicine.

Week 1 RET @ BU

My first week at Boston University (BU) could not have been any more productive.  Initially, my pre-service colleague, Liz and I met with Tim, a fourth year Ph. D. candidate.  Tim did a phenomenal job describing to us what he had been working on in the biophotonics lab.  In sum, they are working on creating a low cost state of the art microscope that will improve the resolution depth and quality of the various specimen.  More, importantly, it will take the technology of a litro (the camera that allows one to take one shot and zoom in on any aspect of the image) into a microscope.  He described a phase contrast imaging technique that uses an LED light, which is added to a standard light microscope to allow for increased image quality in depth.

The possible application of this technology is to add another dimension to rapid diagnostic tests (RDT).  To put it in context, one possible use of this is to use it to diagnose whether a patient have the parasite that causes malaria in their blood.  Unfortunately, there are already RDTs that identify the disease with much more ease and more appropriate for developing countries (dipsticks).

We are now looking into using this technology to diagnose sickle cell anemia (SCA).  Liz and I have been reading much literature about malaria and the various diagnostics tools available.  I've already improve my knowledge about the disease:

• Caused by four different species of plasmodium
• P. falciparum - most common and deadliest
• P. vivax
• P. malariae
• P. ovale
• Cycles of parasite reproduction in the blood causes the observed symptoms:
• fever
• headache
• chills
• vomiting
• Diagnostic tools varies
• RDTs are used in the field
• Microscopy is used in the clinics
• Treatment - artemisinin for which some P. falciparum are already developing resistance
• Vaccine? since parasites resides inside the human host cells, it is hidden from the activation mechanism of the immune system.

Now, we have turn our focus onto sickle cell anemia.  our first objective is to once again is to acquire some background on the topic.  Second, we are to find a vendor that carries sample sickle cell blood so we can place an order.  I've initiated the search for a vendor and so far it does not look too promising.  Animals are used as model organisms for testing potential therapeutics and as of now some of the possibilities are mouse, rat and rabbit.  Nonetheless, the search continues...

Some of the questions I currently have about the PAW:

1. Can it differentiate between SCA and the SC trait?
2. Can it be used to test for other blood related disorders such as hemophilia, diabetes, leukemia...?