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A variety of disposable skin puncture devices are available that will ensure a safe procedure when used properly. Most devices have a spring loaded feature for the blade or the lancet. Once activated, the lancet will automatically puncture the skin using a quick motion. The lancet will immediately retract back into the housing of the device. This design eliminates the possibility of accidental needlestick injury to the phlebotomist. All devices are single use only and must be disposed of in an approved sharps container immediately after activation. An example of an approved sharps container is shown below.It is very important for the phlebotomist to use the puncture device that is designed specifically for the procedure to be performed. Lancets are manufactured to ensure incisions to a safe depth and length. A special lancet designed for use on babies less than 5 pounds is available and should always be used when performing a heelstick on a premature infant. A lancet designed for puncture of a finger should not be used for the puncture of a heel. A heel incision device is set to a maximum penetration depth of 2.0 mm (some facilities may require even shallower penetration for premature infants). Fingerstick devices may exceed this maximum depth of penetration that is allowed for an infant heel puncture. The image on the left illustrates a lancet style that is typically used for fingersticks. the image on the right is one style of puncture device that is used for heelsticks.

Factors that affect staining include: Concentration of the Dye - The greater the concentration of the dye, the more the dye is bound to tissue components.Temperature - An increase in temperature increases the rate at which the dye diffuses throughout the tissue sample. It can also alter tissue components so that they are more receptive to dye penetration. pH of the Staining Solution - Cells and other tissue elements often have an affinity for stains/dyes with specific pH ranges. Thus, the pH of the staining solution can have a direct impact on the ability of a dye to bind with its intended tissue element. Tissue fixation - Fixation alters and reorganizes certain molecular structures in tissue samples so that they have an increased permeability and are more receptive to staining. Unfixed tissue elements have limited binding sites for dyes.

Factors that affect staining include: Concentration of the dye - The greater the concentration of the dye, the more the dye is bound to tissue components.Temperature - An increase in temperature increases the rate at which the dye diffuses throughout the tissue sample. It can also alter tissue components so that they are more receptive to dye penetration.pH of the staining solution - Cells and other tissue elements often have an affinity for stains/dyes with specific pH ranges. Thus, the pH of the staining solution can have a direct impact on the ability of a dye to bind with its intended tissue element.Tissue fixation - Fixation alters and reorganizes certain molecular structures in tissue samples so that they have an increased permeability and are more receptive to staining. Unfixed tissue elements have limited binding sites for dyes.Mordants - A chemical solution called a Mordant must be used to bind certain dyes to the certain tissue elements or can be to intensify the staining results of the procedure.

HIV consists of nine genes. Three of the genes provide genetic information for the capsid proteins, envelope proteins, and viral enzymes. The other six genes are regulatory genes, controlling functions such as uncoating of the HIV genome and the penetration of host cells. Gene Number Abbreviation Gene Function 1 gag capsid proteins 2 pol viral enzymes 3 env envelope proteins 4 vif regulatory gene 5 tat regulatory gene 6 vpu regulatory gene 7 nef regulatory gene 8 vpr regulatory gene 9 rev regulatory gene

After penetration of the cell membrane by the gp41, the HIV capsid enters the cell's cytoplasm. Next, cellular enzymes strip away the capsid so that the HIV genome is released. Also stripped away are proteins p24 and p17. Protein 24 coats the HIV genome and protein 17 lines the inside of the capsid.