Final answer:
To distinguish sickle cell crisis from infection, blood smears under microscopy can reveal sickle-shaped cells. Genetic testing using restriction endonuclease Cvn-1 can confirm sickle cell anemia by identifying the altered DNA sequence. Pathogens seen in stained blood smears along with clinical signs can indicate infection.
Step-by-step explanation:
To distinguish a sickle cell crisis from infection, medical professionals can utilize a variety of diagnostic tests. One key difference is in the blood smear appearance: sickle cells are characteristically crescent shaped, while normal cells are disc shaped. If a patient known to have sickle cell anemia presents with symptoms such as high fever, severe pain, and swelling, a blood smear can be examined under a bright field microscope at 535x magnification to confirm the presence of sickle-shaped cells.
Additionally, the diagnosis of sickle cell anemia can be confirmed using a genetic test with restriction endonuclease Cvn-1. This enzyme cuts the DNA at specific sites, and due to a single nucleotide alteration in sickle cell anemia (from CCTGAGG to CCTGTGG), one of the recognition sites is lost. Therefore, the number and sizes of DNA fragments resulting from the Cvn-1 cleavage can indicate whether a person has normal hemoglobin A (A/A), is a carrier (A/S), or has sickle cell anemia (S/S).
On the other hand, to detect an infection, a physician will look for evidence of infection by examining Wright-Giemsa-stained blood smears for pathogens, in addition to other clinical signs and laboratory tests indicating an infection.